Affects SharePoint 2013 (Compatibility mode 2010)
The user has read permission on a library (as stated by "check permission" feature). Inside this library, there is an excel file. The mentioned file opens in the client application. When the user saves the document, Excel tries to save it back to the SharePoint document library. Since the user doesn't have write permission, it always fails.
This behaviour started to show up a few weeks ago and never happened before. The client environment consists of Windows 7 and Office 2010 Professional Plus.
Does anyone know what the cause of this could be? Any specific update I should take a look at? It seems very strange to me.