Lock/Unlock Custom Fields
Available since 1.30.*
Some added fields by different JIRA versions and additional plugins can be locked .
According to the Atlassian documentation, the only option unlock this fields is do changes to the database How to unlock a Locked Jira Software Field.
From now, you can do it without having to access the database. Go to Custom Fields setting page in JIRA and select option Lock Field/Unlock Field from Actions menu.
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