On a SharePoint Server 2010 a user tries to open a Word document from a library that requests checkout. He is using Firefox:
- clicks on the document
- the document opens in read only mode in the Word Web App
- he then clicks "Open in Word"
- a dialog asks him whether he wants open it read only or check out the document first
- he chooses check out and gets this error message:
Which translates to: "This document could not be checked out. You may not have permission to check out the document or it is already checked out or locked for editing by another user."
Well, the document is not checked out by another user and he has rights to check it out (if he directly clicks check out in the context menu of the list item, the document is successful checked out).
Microsoft Office Professional Plus 2010 and the Plugin for Firefox are installed on the client.