Problem
When you migrate from one JIRA Cloud instance to another (using a Backup/Restore), all Connect add-ons (including JMWE) installed in your instance would break because of the "clientKey". This is due to a known JIRA Cloud bug AC-1528.
Solution
If you wish to use the old instance, the only solution is to reach out to Atlassian Support and ask them to fix your "clientKey". Once they fix it, you should be able to reinstall the add-on. If not, our support will clear your existing registration with us and then you will be able to reinstall the add-on.
Reinstalling of the add-on will not modify your configured workflows. However, while the add-on is inactive, JIRA might start failing transitions which have JMWE post-functions configured, so you want to minimize the time between un-installation and re-installation of the add-on.
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