Steps to resolve error:
Unlock package by running hpkgunlk command
-hpkgunlk MR-xxxxx -b broker_name -en project_name -usr user_name -pw password -o=hpkgunlk.txt
-check log file for command output X:\Users\your-windows-user\hpkgunlk.txt
-Names with spaces should be enclosed between "" ""
-check broker name, for example, lixscm or lixscm/cascm_it
-verify complete package name, like in MR-xxxxx or "MR-xxxxxx #BCDE-1001 BCDE AppServer - prod"
(note that brackets used)