Description
Due to a problem in the Intel® Quartus® Prime Pro Edition Software version 19.1, you may see this internal error when opening a project from an earlier version of the Intel® Quartus® Prime Pro Edition Software in version 19.1 for the 1st time.
Resolution
To work around this problem, delete the qdb folder before opening the project in version 19.1
This problem is scheduled to be fixed in a future release of the Intel® Quartus® Prime Pro Edition Software.