ERROR: SAP-System not installed properly. (TADIR HEAD SYST missing.)

I got the error:

This is tp version 380.09.46 (release 741, unicode enabled)

HALT 20141014150533

ERROR: SAP-System not installed properly. (TADIR HEAD SYST missing.)

ERROR: EXIT(16) -> process ID is: 5608

tp returncode summary:

TOOLS: Highest return code of single steps was: 16

ERRORS: Highest tp internal error was: 0233

tp finished with return code: 233

meaning:

  SAP-System not installed properly (HEAD SYST)

I tested the TADIR table and found that is corrupted, the record for HEAD SYST is missing.

I cannot update this record by using SE06 - it woks, but nothing changes.