Issue Summary

Unable to change "Default Assignee" in the Assignee hidden field in the Request form, it throws an error "Enter a valid preset value".

Steps to Reproduce

1. Add the "Assignee" field to the Request form and configure the "Default assignee" user value.
2. Now, for the configured user in the Default Assignee, remove the "Agent JSM Product" access.
3. Got to the Request form and got an error in front of the Assignee field "Enter a valid preset value".
   

Expected Results

Able to expand the "Assignee" field and update the "default assignee" value.

Actual Results

The below error is thrown on the Request form:

Enter a valid preset value

Along, with the project settings error:
"This service project has configuration problems and may not work as expected."

Workaround

1. If aware of the default assignee, provide JSM - Agent product access and change the default assignee afterward.
2. Remove the Assignee field from the Request form, add it back, and configure the required default assignee.