I just went through upgrade procedure from 6.3.13 → 7.0.* → 7.1.* → 8.0.* and we are getting no results when searching for library from Admin Settings / Libraries section. Keep in mind that libraries show up and we can navigate to different pages to find stuff, but top search doesn’t work.
Checked my seafile.log file and saw MYSQL error that showed "COLLATION ‘UTF8_GENERAL_CI’ is not valid for CHARACTER SET ‘latin1’.
Has anyone had this issue after upgrading and what was the fix?