backfilling start date error

I have one specific complaint but when I’m creating/testing a new event frame it is the worst.
When backfilling a single analysis, the start time and end time boxes will throw an error and not allow the you to start the backfill if at any time the string does not comply with time string rules.
When you’ve completed the backfill time string, it will not re-enable. This forces you to start over and either copy and paste a time string in there or use the calendar.

Screenshot02 Locked out and must start over