Power Scripts™ for Jira 5.8.x is only compatible with Jira 8.x.
If you have installed an incompatible version, perform the following steps:
Power Apps License Manager.
Uninstall SIL Engine™.
Uninstall Power Scripts™ for Jira.
Uninstall the Power Apps License Manager.
Install a version of Power Scripts™ for Jira that is compatible with your Jira version. SIL Engine™ and the Power Apps License Manager should now have the right versions as well.
After you uninstall SIL Engine™ and the Power Apps License Manager, some apps may remain disabled, so you may need to re-enable them manually.