And a refresh doesn’t fix this?
Try the admin login backdoor?
And once you’re in please check
yoursite/logs to know what is not working.
So that unknown error is actually bad CRSF
Probably a configuration issue at your install.
Please share some details about your install?
e.g. host OS, Install method, reverse proxies etc.
BAD CSRF” usually means https isn’t configured properly.
centos with plesk
what instalation isius share ? app.ywl file?