The problem the next.
When you open an excel file in a custom application (office 2010) from the document library, you receive a "Run-time error '52' Bad file name or number"error. If the same document open in office 2013, all open and read and edit without errors.
SharePoint 2013 Standard Version.
What to do and how to fix the error, I don't know. So please help you, maybe someone already faced with this problem.