I believe it is referring to the ODBC file.
Recommend uninstalling and reinstalling WB5 - making sure to reboot after both the uninstall and reinstall procedure.
This is recommended before having to dig further to find the issue, as this is a system file, and you should not be getting this message in normal circumstances.
Note - it would also be recommended to delete any "WindowBlinds" folder left in "C:\Program Files\Stardock\Object Desktop" folder after uninstalling and before reinstalling. Make sure to copy any skin folders existing in the "WindowBlinds" folder, that were downloaded seperately from the WB5 installation to a temporary folder before deleting.