"We are currently updating the migration service" message in JCMA

Issue Summary

Customer can sometimes receive warning/error message "We are currently updating the migration service" in JCMA while running a migration plan.

Steps to Reproduce

1. Run a Migration Plan through JCMA;
2. When reviewing the Migration Checklist, admins running the assistant can receive the before-mentioned message.

Expected Results

• The message "We are currently updating the migration service" should not appear, or in case the destination cloud site is for some reason unavailable/unreachable, a better/self-explanatory/complete message should be displayed to the customer running the migration plan, such as:

"<Destination Cloud Site> is unreachable at this moment. Please try again or contact the Migration Support in case the issue persists."

Actual Results

Customers end up getting a really generic message "We are currently updating the migration service" that is not very helpful for an initial analysis.

Workaround

Some workarounds that were found to be effective:

• Make sure you are using the correct JIRA's base url before migration;
• Please re-migrate the project by re-authenticating to the cloud instance (Jira server Administration > System > Migrate to cloud > Create new migration > Connect to cloud > click "Choose cloud site" button > click "Change Account" > re-enter the login credentials -> select cloud site);