How to unlock user blocked for moderation

One of my admin user is blocked for moderation. Got two questions here.
1. I do not know why this happened
2. How to unlock the user ?
See in dashboard I see his blocked messages but I cannot see how to unlock the messages and the user !!
0
Comments
Make sure in permissions for his user group(s) that
Vanilla - Approval - Require
is not ticked.
Great thank you !
Just last question : how to clean the messages waiting for approval ??
I do not see any button to delete or approve those messages.