The server block is not well formed. Troubleshoot issues with windows SharePoint services

Issue: 
An error occurred during the processing of /Testsite/Documents/Forms/AllItems.aspx. The server block is not well formed.
Troubleshoot issues with windows SharePoint services.

Resolution 1:

• Go to your document library and change the AllItems.aspx part @ the end of your url to webfldr.aspx
• Click on [Settings] and choose [Document Libary Settings]
• Create a new view, name it temp or so (you can use allitems as a start of your view)
• Again go back to your document library and change AllItems.aspx again to temp.asxp (or the name you choose).
• Click Actions and choose [Open with Windows Explorer]
• Change AllItems.asxp to AllItems_old.asxp
• Rename temp.asxp to AllItems.asxp
• If you browse to your document library, you will now see that the view is still named “temp’, open [Settings] again and choose [Document Libary Settings]Settings]
• Change the Temp view, make it default and rename the view name to AllItems

Resolution 2:

Load your site in SharePoint Designer and find the file in question, for the library impacted. You should find that the file has a blue “!” icon next to it, indicating it has been modified/customized/unghosted. Right click and choose Reset to Site Definition and you should be back in business.