HERES TO COPILOT TROUBLESHOOT I DID YESTERDAY ##### You said: mobiletest in the desktop - url displays as **but when i click share and copy the link it is** [https://.sharepoint.com/:u:/r/sites//SitePages/[mobiletest.aspx](https://www.microsoft365.com/hwav2/chat/conversation/]() ###### Copilot said: This is the clue I was looking for. You've now proved all of the following: - The site homepage has been successfully changed to [mobiletest](https://.sharepoint.com/sites//SitePages/mobiletest.aspx). Desktop access to the site root now opens that page. - [mobiletest](https://.sharepoint.com/sites//SitePages/mobiletest.aspx) is a brand new page containing virtually no content. - The SharePoint app still hangs on a white screen when opening the site. - Opening pages from **Site Pages** works. - Opening document libraries works. That means we can now rule out: ❌ Home.aspx content ❌ News web parts ❌ Quick Links web parts ❌ Homepage page corruption ❌ Homepage assignment The fact that a completely new homepage exhibits the same behaviour is the key result. ### What I now think is happening The mobile app is not actually failing on the page itself. Earlier you captured a URL containing: Plain Text _layouts/15/mobile/mblwp.aspx?...default.aspx That's SharePoint's mobile routing layer trying to resolve the site landing page. Since: - Any page can be opened from **Site Pages** - The site root hangs - Multiple group sites are affected - The homepage page itself is no longer the same page the common denominator is the **site landing/navigation experience**, not the page. ### One test I'd do immediately On the affected phone, don't use the SharePoint app. Open Chrome and browse directly to: Plain Text [https://.sharepoint.com/sites//SitePages/mobiletest.aspx]() (not the shared `/ :u:/r/` link) I want to know whether: - The page opens, or - Chrome redirects to `mblwp.aspx` and fails again. ### Another thing to check Are all affected sites: - Group-connected Team Sites? - Hub-associated sites? and are there any sites that **don't** exhibit the problem? For example: - A Communication Site - A separate project site - A brand-new test site If a brand-new Team Site also fails, I'd be leaning heavily towards a SharePoint Online/mobile application issue rather than anything specific to . At this point, you have already done enough testing to conclude that the issue is **not with** [Home](https://.sharepoint.com/sites//SitePages/Home.aspx) **or** [mobiletest](https://.sharepoint.com/sites//SitePages/mobiletest.aspx) **themselves**. The evidence points to the way the mobile client is opening the site, not the content of the page. ## ![Sharepoint type](https://res.cdn.office.net/midgard/versionless/fluentui-resources/4.0.5/assets/item-types/24_1.5x/spo.svg) Sources ##### You said: it threw up an error and asked me to switch to pc view which i did and it opened ###### Copilot said: That is a **very strong indicator that the problem is the mobile view itself**, not the page, not permissions, and not authentication. Your test sequence now shows: - ✅ `mobiletest.aspx` exists and opens in desktop mode. - ✅ The site homepage mapping can be changed and desktop follows the new mapping. - ✅ Site Pages opens. - ✅ Document libraries open. - ✅ Forcing **PC/Desktop View** allows the page to open. - ❌ Mobile view hangs or redirects to the legacy mobile handler (`mblwp.aspx`). The fact that **switching to PC view immediately works** is the key result. That means: > The content can be rendered by SharePoint, but the mobile experience cannot render or route to it correctly. At this point I would stop investigating page content and focus on the mobile experience itself. ### My assessment You've effectively ruled out: - Authentication issues - Permissions issues - Homepage corruption - Home.aspx corruption - Navigation link errors - News web part problems The evidence points towards either: 1. A SharePoint mobile app/mobile rendering issue affecting your tenant. 1. A SharePoint Online mobile experience issue affecting modern Team Sites. ### I'd now check one final thing Open the site in Chrome on the phone and: 1. Tap the browser menu. 1. Select **Desktop site** immediately. 1. Browse to the site root. If that works consistently while the normal mobile view fails, that further confirms the issue is isolated to SharePoint's mobile experience. ### Practical workaround For your users, a temporary workaround would be: - Use **Desktop Site / PC View** in the mobile browser. - Or access libraries and pages directly via Site Pages rather than the site Home landing page. ### What I would do next as an admin Raise a Microsoft 365 support ticket and provide the specific evidence you've gathered: - Mobile browser redirects through: ``` /_layouts/15/mobile/mblwp.aspx ``` - Desktop view works. - Site Pages works. - Document libraries work. - Brand-new homepage (`mobiletest.aspx`) exhibits the same behaviour. - Multiple Group/Team sites are affected. That's a very strong technical case that the issue lies in SharePoint's mobile experience rather than your site configuration. One final question: **is this happening on both iPhone and Android, or have you only tested on one platform so far?** ## ![Sharepoint type](https://res.cdn.office.net/midgard/versionless/fluentui-resources/4.0.5/assets/item-types/24_1.5x/spo.svg) Sources ##### You said: why would it happen in sharepoint app tho? ###### Copilot said: Because the SharePoint app is **not just a browser wrapped in an app**. What you've discovered is actually consistent with how the SharePoint mobile app works: When you open a page from **Site Pages**, the app is opening the page directly (`SitePages/Home.aspx` or `mobiletest.aspx`). That works.+1 When you open the **site**, the app first tries to resolve the site's landing experience and navigation. Earlier you captured it redirecting through SharePoint's mobile handler: Plain Text _layouts/15/mobile/mblwp.aspx?...default.aspx 1. That mobile route appears to be what is failing, not the page itself. The strongest evidence is: - You changed the homepage from **Home.aspx** to **mobiletest.aspx**. - Desktop immediately started opening **mobiletest.aspx**, proving the homepage assignment changed correctly. - The SharePoint app still hangs white. - Opening **mobiletest.aspx** directly works. If the page were the problem, changing to a brand-new blank page would have fixed it. It didn't. My honest assessment is that you've narrowed this down to one of two things: ### Most likely A bug in the SharePoint mobile app or SharePoint Online mobile navigation layer affecting modern Team Sites. ### Less likely A site navigation configuration common across your Team Sites that the mobile client is mishandling. The fact that: - multiple sites are affected, - pages open directly, - libraries open, - the site landing route fails, all points away from content and towards the mobile site-navigation experience itself. If I were raising this with Microsoft, I'd summarise it as: > "SharePoint mobile app shows a white screen when opening Team Sites. Site Pages and document libraries open normally. Direct links to pages work. Changing the homepage to a brand-new blank page does not resolve the issue. The mobile client appears to redirect through `/_layouts/15/mobile/mblwp.aspx` and fails to load the site landing page." That's actually a very strong support case because you've already eliminated most of the normal causes. ## ![Sharepoint type](https://res.cdn.office.net/midgard/versionless/fluentui-resources/4.0.5/assets/item-types/24_1.5x/spo.svg) Sources ##### You said: Summarize key points for Microsoft support ###### Copilot said: Here's a concise support summary you can paste directly into a Microsoft 365 support ticket: --- # SharePoint Mobile App / Mobile Browser Issue ## Tenant **.sharepoint.com** ## Issue Summary Users are unable to open SharePoint Team Site homepages from the SharePoint mobile app and mobile browsers. The site loads correctly on desktop browsers, but when opened through the SharePoint mobile app or the site's Home navigation, the page displays a white screen or fails to load. This issue affects multiple Group-connected SharePoint sites. ## Troubleshooting Performed ### Works Successfully - Desktop browser access to SharePoint sites. - Desktop browser access from outside the corporate network. - OneDrive mobile app access. - SharePoint document libraries on mobile devices. - Classic SharePoint pages such as: Plain Text /_layouts/15/viewlsts.aspx - Site Pages library on mobile. - Direct opening of pages from the Site Pages library. ### Fails - Opening the site homepage via the SharePoint mobile app. - Opening the site through the site's Home navigation. - Opening the site root URL in mobile view. ### Homepage Testing Originally the site homepage was: Plain Text /sites//SitePages/Home.aspx A brand-new blank page (**mobiletest.aspx**) was created and set as the site homepage. Desktop browsers immediately began opening the new homepage correctly, proving the homepage assignment updated successfully. However, the SharePoint mobile app still displayed a white screen when opening the site. This demonstrates that the issue is not related to the original Home.aspx page content. The test page contains only minimal content and no custom web parts. ## Mobile Browser Behaviour When attempting to open the site from a mobile browser, SharePoint redirects through: Plain Text /_layouts/15/mobile/mblwp.aspx The resulting error references: Plain Text /sites//default.aspx and reports: > "The web page might be temporarily down or it may have moved permanently to a new web address." If the browser is switched to **Desktop Site / PC View**, the page loads successfully. ## Additional Findings - No site changes have been made since approximately April 2026. - Multiple affected sites exhibit the same behaviour. - Direct page access works. - Site Pages works. - Document libraries work. - Only the mobile site landing/navigation experience appears to be affected. - Changing the homepage to a completely new page did not resolve the issue. ## Suspected Area The issue appears related to SharePoint's mobile site navigation / homepage resolution layer rather than: - Authentication - Permissions - OneDrive - Page content - Web parts - Homepage assignment Please investigate the SharePoint Online mobile experience and the routing/redirect process used when opening Team Sites from the SharePoint mobile application. --- Evidence regarding the original homepage and the test homepage was verified from the site pages themselves.+1 ## ![Sharepoint type](https://res.cdn.office.net/midgard/versionless/fluentui-resources/4.0.5/assets/item-types/24_1.5x/spo.svg) Sources ##### You said: Explain how to submit this summary to Microsoft support ###### Copilot said: As a Microsoft 365 Global Admin (or SharePoint Admin), the easiest way to submit this is through the Microsoft 365 Admin Centre. ### Option 1: Microsoft 365 Admin Centre (Recommended) Go to the Microsoft 365 Admin Centre: - [Microsoft 365 Admin Centre](https://admin.microsoft.com/) Select: ``` - **Support** - **Help & support** In the description box enter something like: Plain Text SharePoint mobile app and mobile browser issue affecting multiple Team Sites.   Site homepages show a white screen when opened from the SharePoint mobile app or site Home navigation.   Direct access to Site Pages works. Document libraries work. OneDrive mobile works. Desktop access works.   The problem persists after changing the homepage to a brand-new blank page.   Please see attached diagnostic summary. When prompted, choose: - **SharePoint Online** - **Site access/navigation** - **Mobile app** Create the ticket and paste the full summary we prepared into the support request. ```--- ### Option 2: SharePoint Admin Centre Go to: - [https://admin.microsoft.com/sharepoint]() Select **Help & support** (top-right question mark icon). Raise the ticket against **SharePoint Online**. --- ### Information Microsoft is likely to ask for Have these ready: Tenant: **.sharepoint.com** Example site: - `https://.sharepoint.com/sites/` Example affected user(s) iPhone/Android version SharePoint App version Approximate date the issue started Screenshot of the white screen Screenshot of the mobile error referencing: Plain Text /_layouts/15/mobile/mblwp.aspx The fact that a newly created test homepage (`mobiletest.aspx`) also exhibits the issue while opening correctly when accessed directly. ### Suggested Support Case Title Plain Text SharePoint Mobile App - Team Site Home Navigation Fails (White Screen) While Site Pages and Libraries Open Successfully Based on all the testing you've done, you've already gathered far more diagnostic information than Microsoft usually receives in an initial ticket, which should help them narrow it down quickly.+1 ##### You said: mobiletest **in the desktop - url displays as but when i click share and copy the link it is** [https://.sharepoint.com/:u:/r/sites//SitePages/[mobiletest.aspx](https://www.microsoft365.com/hwav2/chat/conversation/SPO_N2VmMDhiMGYtZDc1NS00NmEwLWJlNWQtYzQ5NzE2MGZkN2JmLGZlMWY4OTk5LWM4MWQtNGZkMS1hZWJjLWJkZGJhY2EyMTNiMyxhYTU2NzI3Yy1kMjc3LTQ2ZjgtYmE2OC04ODFiMjQ2ZTZiOTA_01Z32EDI4ZRCVCVIA7RZHZPELML3OTW5XG)?d=w2aaa88991fa04f8e97916c5edd3b76e6&csf=1&web=2&share=IQCZiKoqoB-OT5eRbF7dO3bmAY8]() ###### Copilot said: This is the clue I was looking for. You've now proved all of the following: - The site homepage has been successfully changed to [mobiletest](https://.sharepoint.com/sites//SitePages/mobiletest.aspx). Desktop access to the site root now opens that page. - [mobiletest](https://.sharepoint.com/sites//SitePages/mobiletest.aspx) is a brand new page containing virtually no content. - The SharePoint app still hangs on a white screen when opening the site. - Opening pages from **Site Pages** works. - Opening document libraries works. That means we can now rule out: ❌ Home.aspx content ❌ News web parts ❌ Quick Links web parts ❌ Homepage page corruption ❌ Homepage assignment The fact that a completely new homepage exhibits the same behaviour is the key result. ### What I now think is happening The mobile app is not actually failing on the page itself. Earlier you captured a URL containing: Plain Text _layouts/15/mobile/mblwp.aspx?...default.aspx That's SharePoint's mobile routing layer trying to resolve the site landing page. Since: - Any page can be opened from **Site Pages** - The site root hangs - Multiple group sites are affected - The homepage page itself is no longer the same page the common denominator is the **site landing/navigation experience**, not the page. ### One test I'd do immediately On the affected phone, don't use the SharePoint app. Open Chrome and browse directly to: Plain Text [https://.sharepoint.com/sites//SitePages/mobiletest.aspx]() (not the shared `/ :u:/r/` link) I want to know whether: - The page opens, or - Chrome redirects to `mblwp.aspx` and fails again. ### Another thing to check Are all affected sites: - Group-connected Team Sites? - Hub-associated sites? and are there any sites that **don't** exhibit the problem? For example: - A Communication Site - A separate project site - A brand-new test site If a brand-new Team Site also fails, I'd be leaning heavily towards a SharePoint Online/mobile application issue rather than anything specific to . At this point, you have already done enough testing to conclude that the issue is **not with** [Home](https://.sharepoint.com/sites//SitePages/Home.aspx) **or** [mobiletest](https://.sharepoint.com/sites//SitePages/mobiletest.aspx) **themselves**. The evidence points to the way the mobile client is opening the site, not the content of the page. ## ![Sharepoint type](https://res.cdn.office.net/midgard/versionless/fluentui-resources/4.0.5/assets/item-types/24_1.5x/spo.svg) Sources ##### You said: it threw up an error and asked me to switch to pc view which i did and it opened ###### Copilot said: That is a **very strong indicator that the problem is the mobile view itself**, not the page, not permissions, and not authentication. Your test sequence now shows: - ✅ `mobiletest.aspx` exists and opens in desktop mode. - ✅ The site homepage mapping can be changed and desktop follows the new mapping. - ✅ Site Pages opens. - ✅ Document libraries open. - ✅ Forcing **PC/Desktop View** allows the page to open. - ❌ Mobile view hangs or redirects to the legacy mobile handler (`mblwp.aspx`). The fact that **switching to PC view immediately works** is the key result. That means: > The content can be rendered by SharePoint, but the mobile experience cannot render or route to it correctly. At this point I would stop investigating page content and focus on the mobile experience itself. ### My assessment You've effectively ruled out: - Authentication issues - Permissions issues - Homepage corruption - Home.aspx corruption - Navigation link errors - News web part problems The evidence points towards either: 1. A SharePoint mobile app/mobile rendering issue affecting your tenant. 1. A SharePoint Online mobile experience issue affecting modern Team Sites. ### I'd now check one final thing Open the site in Chrome on the phone and: 1. Tap the browser menu. 1. Select **Desktop site** immediately. 1. Browse to the site root. If that works consistently while the normal mobile view fails, that further confirms the issue is isolated to SharePoint's mobile experience. ### Practical workaround For your users, a temporary workaround would be: - Use **Desktop Site / PC View** in the mobile browser. - Or access libraries and pages directly via Site Pages rather than the site Home landing page. ### What I would do next as an admin Raise a Microsoft 365 support ticket and provide the specific evidence you've gathered: - Mobile browser redirects through: ``` /_layouts/15/mobile/mblwp.aspx ``` - Desktop view works. - Site Pages works. - Document libraries work. - Brand-new homepage (`mobiletest.aspx`) exhibits the same behaviour. - Multiple Group/Team sites are affected. That's a very strong technical case that the issue lies in SharePoint's mobile experience rather than your site configuration. One final question: **is this happening on both iPhone and Android, or have you only tested on one platform so far?** ## ![Sharepoint type](https://res.cdn.office.net/midgard/versionless/fluentui-resources/4.0.5/assets/item-types/24_1.5x/spo.svg) Sources ##### You said: why would it happen in sharepoint app tho? ###### Copilot said: Because the SharePoint app is **not just a browser wrapped in an app**. What you've discovered is actually consistent with how the SharePoint mobile app works: When you open a page from **Site Pages**, the app is opening the page directly (`SitePages/Home.aspx` or `mobiletest.aspx`). That works.+1 When you open the **site**, the app first tries to resolve the site's landing experience and navigation. Earlier you captured it redirecting through SharePoint's mobile handler: Plain Text _layouts/15/mobile/mblwp.aspx?...default.aspx 1. That mobile route appears to be what is failing, not the page itself. The strongest evidence is: - You changed the homepage from **Home.aspx** to **mobiletest.aspx**. - Desktop immediately started opening **mobiletest.aspx**, proving the homepage assignment changed correctly. - The SharePoint app still hangs white. - Opening **mobiletest.aspx** directly works. If the page were the problem, changing to a brand-new blank page would have fixed it. It didn't. My honest assessment is that you've narrowed this down to one of two things: ### Most likely A bug in the SharePoint mobile app or SharePoint Online mobile navigation layer affecting modern Team Sites. ### Less likely A site navigation configuration common across your Team Sites that the mobile client is mishandling. The fact that: - multiple sites are affected, - pages open directly, - libraries open, - the site landing route fails, all points away from content and towards the mobile site-navigation experience itself. If I were raising this with Microsoft, I'd summarise it as: > "SharePoint mobile app shows a white screen when opening Team Sites. Site Pages and document libraries open normally. Direct links to pages work. Changing the homepage to a brand-new blank page does not resolve the issue. The mobile client appears to redirect through `/_layouts/15/mobile/mblwp.aspx` and fails to load the site landing page." That's actually a very strong support case because you've already eliminated most of the normal causes. ## ![Sharepoint type](https://res.cdn.office.net/midgard/versionless/fluentui-resources/4.0.5/assets/item-types/24_1.5x/spo.svg) Sources ##### You said: Summarize key points for Microsoft support ###### Copilot said: Here's a concise support summary you can paste directly into a Microsoft 365 support ticket: --- # SharePoint Mobile App / Mobile Browser Issue ## Tenant **.sharepoint.com** ## Issue Summary Users are unable to open SharePoint Team Site homepages from the SharePoint mobile app and mobile browsers. The site loads correctly on desktop browsers, but when opened through the SharePoint mobile app or the site's Home navigation, the page displays a white screen or fails to load. This issue affects multiple Group-connected SharePoint sites. ## Troubleshooting Performed ### Works Successfully - Desktop browser access to SharePoint sites. - Desktop browser access from outside the corporate network. - OneDrive mobile app access. - SharePoint document libraries on mobile devices. - Classic SharePoint pages such as: Plain Text /_layouts/15/viewlsts.aspx - Site Pages library on mobile. - Direct opening of pages from the Site Pages library. ### Fails - Opening the site homepage via the SharePoint mobile app. - Opening the site through the site's Home navigation. - Opening the site root URL in mobile view. ### Homepage Testing Originally the site homepage was: Plain Text /sites//SitePages/Home.aspx A brand-new blank page (**mobiletest.aspx**) was created and set as the site homepage. Desktop browsers immediately began opening the new homepage correctly, proving the homepage assignment updated successfully. However, the SharePoint mobile app still displayed a white screen when opening the site. This demonstrates that the issue is not related to the original Home.aspx page content. The test page contains only minimal content and no custom web parts. ## Mobile Browser Behaviour When attempting to open the site from a mobile browser, SharePoint redirects through: Plain Text /_layouts/15/mobile/mblwp.aspx The resulting error references: Plain Text /sites//default.aspx and reports: > "The web page might be temporarily down or it may have moved permanently to a new web address." If the browser is switched to **Desktop Site / PC View**, the page loads successfully. ## Additional Findings - No site changes have been made since approximately April 2026. - Multiple affected sites exhibit the same behaviour. - Direct page access works. - Site Pages works. - Document libraries work. - Only the mobile site landing/navigation experience appears to be affected. - Changing the homepage to a completely new page did not resolve the issue. ## Suspected Area The issue appears related to SharePoint's mobile site navigation / homepage resolution layer rather than: - Authentication - Permissions - OneDrive - Page content - Web parts - Homepage assignment Please investigate the SharePoint Online mobile experience and the routing/redirect process used when opening Team Sites from the SharePoint mobile application. --- Evidence regarding the original homepage and the test homepage was verified from the site pages themselves.+1 ## ![Sharepoint type](https://res.cdn.office.net/midgard/versionless/fluentui-resources/4.0.5/assets/item-types/24_1.5x/spo.svg) Sources ##### You said: Explain how to submit this summary to Microsoft support ###### Copilot said: As a Microsoft 365 Global Admin (or SharePoint Admin), the easiest way to submit this is through the Microsoft 365 Admin Centre. ### Option 1: Microsoft 365 Admin Centre (Recommended) Go to the Microsoft 365 Admin Centre: - [Microsoft 365 Admin Centre](https://admin.microsoft.com/) Select: ``` - **Support** - **Help & support** In the description box enter something like: Plain Text SharePoint mobile app and mobile browser issue affecting multiple Team Sites.   Site homepages show a white screen when opened from the SharePoint mobile app or site Home navigation.   Direct access to Site Pages works. Document libraries work. OneDrive mobile works. Desktop access works.   The problem persists after changing the homepage to a brand-new blank page.   Please see attached diagnostic summary. When prompted, choose: - **SharePoint Online** - **Site access/navigation** - **Mobile app** Create the ticket and paste the full summary we prepared into the support request. ```--- ### Option 2: SharePoint Admin Centre Go to: - [https://admin.microsoft.com/sharepoint]() Select **Help & support** (top-right question mark icon). Raise the ticket against **SharePoint Online**. --- ### Information Microsoft is likely to ask for Have these ready: Tenant: **.sharepoint.com** Example site: - `https://.sharepoint.com/sites/` Example affected user(s) iPhone/Android version SharePoint App version Approximate date the issue started Screenshot of the white screen Screenshot of the mobile error referencing: Plain Text /_layouts/15/mobile/mblwp.aspx The fact that a newly created test homepage (`mobiletest.aspx`) also exhibits the issue while opening correctly when accessed directly. ### Suggested Support Case Title Plain Text SharePoint Mobile App - Team Site Home Navigation Fails (White Screen) While Site Pages and Libraries Open Successfully Based on all the testing you've done, you've already gathered far more diagnostic information than Microsoft usually receives in an initial ticket, which should help them narrow it down quickly.+1