A CKUR abend is issued by the check user subtask running in the CA IDMS CV when it detects that a batch job has ended without issuing a FINISH.
If a FINISH is already coded in the program then it means that the statement is never executed. If it is an update job, the CKUR abend will cause all updates made by the job to be rolled back and message DC203005 will be issued.
You can verify if the FINISH is being executed by running the batch job with DMLTRACE=ON in the SYSIDMS file. It will print all DML commands issued by the program. Examine the output to determine the last DML statement issued.