Errors are documented in the log by error messages. Common errors and their causes:
The ABAP/4 command LEAVE TO … before COMMIT WORK cancels the test.
Possible causes:
Values were assigned to an output field in the test case.
No value was assigned to a required field.
Troubleshooting

Proceed as follows to find test errors:
You can also:
The OK code field must first be cleared. Continue afterwards with the deleted OK code.
This procedure is particularly useful in long lists (e.g. Report Writer lists), to check entries or for manual F1/F4 checks.