@willemdh there is an issue with the validation of the ML anomaly detection job configuration fields when editing one of the Logs UI jobs. It is caused by the
custom_settings part of the job config containing a
job_revision field which is present in the Logs UI anomaly detection jobs. I have just raised an issue in the Kibana repo for this, and will get this fixed for the upcoming 7.7.0 release.
Would you be able to confirm what version of Kibana you are running? I would not have expected to see this particular issue with the validation of the job configuration occurring prior to 7.7, so knowing your Kibana version will allow us to confirm if this is the issue you are seeing.