When commiting an issue has an error, no details are shown on the interface

Issue Summary

When committing changes, like a new issue, the interface doesn't give any means for the user to know why it failed.

While in the interface the very generic error "Could not be committed for unknown reasons" is thrown, the logs have the error.

Steps to Reproduce

Example of trying to set an invalid assignee:

1. Set a project administrator as the default assignee
2. Set the project administrator user as inactive
3. Create an issue in Advanced Roadmaps
4. Attempt to commit the changes

Expected Results

An error that the user can take action on.

Actual Results

The user gets this error:

The below exception is thrown in the atlassian-jira.log file:

/rest/jpo/1.0/issues/commit [c.a.r.j.c.scenario.issue.IssueScenarioEntityCommitExceptionHandler] Exception when trying to commit issue: Specific error details: {assignee=The default assignee does NOT have ASSIGNABLE permission OR Unassigned issues are turned off.}.

Workaround

Currently there is no known workaround for this behavior. A workaround will be added here when available.