Please check if you have the write permission in the file StaadPro20.07.10.ini(For SELECTseries 5) OR StaadPro20.07.11 (For SELECTseries 6) located C:\ProgramData\Bentley\Engineering\STAAD.Pro V8i SS5 OR C:\ProgramData\Bentley\Engineering\STAAD.Pro V8i SS6 respectively.
Note: C is the drive where STAAD.Pro is installed.
Thank you.