Cognos Error: DPR-REQ-0760

DPR-REQ-0760 Invalid Operation “/” “” “”.
noSession Gj48hwdsGvysdC9wdvw2Gd4qqyG2GqG4dhh4jv9v 0 Thread-13 DISP 2531 1 Request Failure PRS-REQ-0760 Invalid Operation “/” “” “”

All users are receiving error “DPR-REQ-0760 Invalid Operation “/” “” “”.” when trying to run reports after a recent restart of the IBM Cognos 8 servers

Verify the Cognos servers were started in the correct order
Ensure the content manager component is started first, before the report servers