Excel Web App causes .xlsx files to become un-editable on Windows Phone 8

Hi all –

So there continues to be some confusion on this issue and I want to try and resolve it in one comprehensive response that hopefully covers all sides of this and addresses all your questions. This response will be marked as the new Answerto this thread and the thread will then be locked.  We are happy to address any questions or issues you have but these new questions or comments are best addressed in new issue threads you can create at answers.microsoft.com.  Once again we apologize for any inconvenience this particular issue may have caused you. 

To summarize..the issue is that some of you have been unable to edit workbooks on your phone in Excel for Windows phone after a ‘save’ of the file in Skydrive or Office Web Apps server.  The 'bug' was introduced in Skydrive on Jan 24 and in Sharepoint/ Office Web Apps server as part of the March Public Update.

**If you experience the issue with files in Skydrive:**This issue has been fixed for Skydrive.  Any ‘new’ Excel files created in Excel Web App as of today (or later than February 19, 2013 when we shipped the fix for this) can now be successfully edited in Excel for Windows Phone.  For files that were created or last saved before February 19, you will first need to open those files in Excel Web App (or Excel desktop client), make a change to the file (edit a single cell for instance) and then save the file back to Skydrive for the file to be editable again on the phone.  Excel Web App has ‘autosave’ so simply closing the file is sufficient after making the change. 

**If you experience the issue with files in Sharepoint 2013/Office Web Apps 2013 (on premise deployments)**If you are experiencing the issue described in this thread and it is related to your own (on premise) deployment of Sharepoint and Office Web Apps Server, you can address it by installing a couple updates from the April Public Update.  The specific updates you would need are:

·         Security Update for Microsoft SharePoint Enterprise Server 2013 (KB2737969) 64-Bit Edition

·         Update for Microsoft Office Web Apps Server 2013 (KB2810007)

Please remember that as in the case of Skydrive, you will need to do a 'Save' on the affected file using Excel Web App or Excel desktop client to allow the file to be editable on Excel for mobile phone. 

**If you still cannot edit workbooks on your phone after following above steps:**If you are still having problems editing workbooks on your phone after following these above steps, it is an issue that is (unfortunately) By Design, meaning you are hitting an inherent limitation of the product.  There are some features (‘unsupported features’) that can block an Excel file from being viewed or edited in Excel Web App, and in Excel for Mobile.   These are inherent limitations of these products.  We are working to remove many of these blocking issues..it’s a priority for our teams. But it’s important to understand that these limitations do exist currently.  You won’t unfortunately be able to view or edit 100% of all features in the web app or phone.   

·         For help understanding issues with unsupported features in Excel for Mobile phone:

To know what features may cause your workbook to not be editable in Excel for Windows Phone, please refer to this support article.  Look for the link there that says “Why can’t I edit some Microsoft Office documents on my phone.”  The info there helps identify what features are not supported in the phone and which may cause you to see the “Can’t Edit Workbook” message at the top of the view when viewing on the phone.  

·         For help understandingissues with unsupported features in Excel Web App:

To understand the story around unsupported features that may block viewing or editing in the Excel Web App, please refer to this support article.  Some features such as Sheet Protection can block the file from being opened at all in the browser.  Some features only block editing of the file in the browser. 

Once you understand what features are blocking,  you can then consider whether it is an option for you to remove these features from your workbook. 

Thank you for your feedback and patience while we work through this issue. And thanks for using Excel Web App!

-Rob