When a customization GUI or licensed core is opened, or when a licensed core is generated, CORE Generator fails with a "_wincg.exe" error.
Non-licensed cores generate without error.
The likely cause of this problem is the number of licenses in the license directory (>100 licenses).
This problem has occurred a number of times from Xilinx Engineers who have opted to generate all available licenses from the license generator.
Any time the CORE Generator tool issues a command to check the license status of a core (e.g., when a customization GUI, a licensed core is opened, or when a licensed core is generated), an error is issued.
To work around this issue, remove any unneeded licenses from the license directory. Create a holding directory for all available licenses and copy the licenses to the license directory, as needed.
In ISE Design Suite 11.2, Accresso has implemented a check in FLEXnet licensing to catch the path limit before the fatal error occurs. However, the same work-around is required to resolve the issue. Xilinx is consolidating license files where possible to make this issue less likely to occur.