Error: Change model cannot be modified for in progress Change Requests on new change request

[srushikesan]

When any new change is created/Submitted after filling all mandatory fields  getting this "Error: Change model cannot be modified for in progress Change Requests"

[srushikesan]

I have found the solution why this is occurring on new state(While Creating)

Its Because i have created on BR with after update insert/update to make CAB Required as true.

On Creating Change this field is getting updated as insert.

So it is updating the Model Field to emergency as CAB Required true.
My issue is resolved.