ClearCase failed to create branch

Error message:

cleartool mkbranch BRANCHNAME FILENAME.rtlogpkg
cleartool: Error: Operation "create_branch" unavailable for manager "petalrt_file_delta"
        (Operation pathname was: "C:\Program Files\Rational\ClearCase\lib\mgrs\petalrt_file_delta\create_branch")
cleartool: Error: Unable to store new version.


Solutions:
1. Find another ClearCase client machine, copy mgrs folder (C:\Program Files\Rational\ClearCase\lib\mgrs)

2. Replace to mgrs folder on the ClearCase client machine which has error message above.