Adding participants from the Customer Portal does not work when there is an inconsistency with any other custom field

Issue Summary

When we try to add participants from the Customer Portal Jira, it does not work.

Steps to Reproduce

1. Go to the customer portal
2. Open a request
3. Try adding a participant to the request.

Expected Results

A new participant is added to the request.

Actual Results

Nothing happens.

Notes:

• From the Development tools, a 500 error is thrown when adding, and a 400 error is thrown when removing, but the errors are generic and nothing is found in the application logs.
• It was found by hbarnett that, when adding a participant, Service Desk is validating all custom fields, if there is an inconsistency with any of the custom fields, like having an invalid option or any issue at all, it is impossible to add request participants from the Customer Portal.

Workaround

To fix any inconsistent custom field. Raise a support request to assist you in finding the inconsistency that is provoking the error.