Disabling ITSM features throws an error if the relevant issue type is not available

Problem

Trying to disable ITSM features throws an error if the relevant issue type is not available in the project.

Steps to Reproduce

1. Go to your project > Project settings > Issue types
2. Click on Actions > Edit issue types
3. Remove the issue type (Service Requests, Changes, Incidents, or Problems) from the scheme by dragging it and dropping into the "Available Issue Types" column > click on Save
4.  Go to Project Settings > Features
5.  Try to disable the ITSM feature for the issue type that you disabled
6.  Observe the behavior

Expected Results

The feature is disabled

Actual Results

An error message appears saying "We couldn't disable Service Requests."

{ "errors": [

{ "errorMessage": "One or more request types in [1223] are either not exist or invalid in project xxxx" }

], "reasonKey": "jsm.requesttype.invalid", "reasonCode": "400"

Workaround

Re-add the issue type back to the scheme and try again

Notes

Generic error message when trying to deactivate ITSM features