When processing an expense run and the generate payment claim is not working, this is because of a trip with data issues.
The purpose of the generate payment claims is to move all trips at a status of approved to processed and also generate a claim for each trip.
If the trips have not moved to processed and no claims are generated, a support analyst will need to review the logs to determine the trip with data issues.
Please raise a support case and reference this article, include the expense group and run number.