Cannot Edit Workflow Scheme with error Issue Type does not exist

Summary

When modifying a Workflow Scheme, the following error is displayed: "A issue type with ID ‘10200’ does not exist"

Cause:
The Issue Type has been deleted but it is still linked to the workflow.

Environment

This is the most up to date JIRA Cloud environment, but is likely present on JIRA Server as well.

Steps to Reproduce

1. Delete any issue type for that is being used by an active workflow.
2. Attempt to edit the workflow scheme.

Expected Results

Workflow scheme is editable.

Actual Results

You will encounter an error similar to "A issue type with ID '10200' does not exist.
The ID will be different but the error message will be the same.
 

Workaround

Option A) Recreate the Workflow Scheme from scratch (not Copy scheme as the copy contains the corruption) and reassign Projects to that new Scheme.

Option B) Manually fix the database:
The current discovered workaround is to find the Scheme Entity in the DB and remove it, which will remove the link between the issue type and workflow. The following SQL was run in the DB to remove all traces of the issue type that had been deleted. Please note that the issuetype (in this case '10200') will be the number in the error message.

select * from workflowschemeentity where issuetype = '10200';
  id   | scheme |        workflow        | issuetype
-------+--------+------------------------+-----------
 10706 |  10700 | FDBUGS Workflow | 10200
(1 row)

Manually delete the relation of that Issue Type to active and inactive workflow schemes:

delete from workflowschemeentity where issuetype = '10200';
delete from draftworkflowschemeentity where issuetype = '10200';