Sometimes after upgrading Jira instance, Secure Fieilds plugin shows as incompatible and regular update procedure won’t work. Different It is caused by differences in JIRA Java API, that’s why different Jira versions require a different package of Secure Fields because of differences in JIRA Java API.
In order to fix it, you will have to uninstall the app manually and install the current version by searching for Secure Fields in Find new apps section.
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