Description
Due to a problem in the Quartus® II software versions 13.0 or earlier, you may see this error if you try to open a corrupt or invalid Conversion Setup File (.cof), in the Convert Programming Files window.
Resolution
To work around this problem, generate a new .cof in the Convert Programming Files window.
This problem is scheduled to be fixed in a future release of the Quartus II software. In a future release, the software is scheduled to generate a message indicating the .cof is invalid instead of generating an internal error.