Excel Unable To Read File

BTW, there are 2 XLSTART folders in your computer.

C:\Program Files\Microsoft Office\Office14\XLSTART
C:\Users\win7\AppData\Roaming\Microsoft\Excel\XLSTART

Then clean up the StartUp folder contain HIDDEN FILES. The path of START UP folder:

C:\Users\win7\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup

And you can also recreate the xlb file at the same time. you can rename the xlb file as Excel14.xlb.old and when you open the excel file it will recreate this xlb file automatically.
This xlb file under:
C:\Users\win7\AppData\Roaming\Microsoft\Excel

I fix this issue by clean up the STARTUP folder. :)

Hope it can also work for you.