Underscores not allowed in login username

Hello all,

Discovered an unfortunate bog - maybe it’s documented, but I haven’t seen it.

If you select an admin username that has an underscore, the login will not recognize it.

For example:
username: admin_Next
password: mySuperIncrediblePassword

The install is successful, but you will not be able to login in. So far, in this instance I have had to reinstall NC with a “non-underscore” username.

Just some advice for anyone installing NC and unable to login for some reason!


This sound a bit strange. Please file a bug at https://github.com/nextcloud/server/issues and mention the version, the exact procedure and possible errors in the logfiles (server, nextcloud, browser). Make sure that no browser extension is blocking some code from running and your super incredible password is complex enough.

This happened in the very latest update as well as the one just before.

I’ll file the bug report.