Message SAP /ISDFPS/FORCE336 - Infotype 1019 (quota planning) for Op/Ex &-& could not be changed

Diagnosis
The attempt to change infotype 1019 -contingent planning- failed.

System Response
The attempt to change the corresonding contingent in infotype 1956was cancelled.

Procedure
Check whether you or someone else is blocking the Customizing tablesfor contingent planning. Then try to change the correspondingcontingent again.