See https://discourse.phabricator-community.org/t/user-cant-logout/2783.

Configuring an install so new users do not have access to any spaces is not really supported (see: T12421, T9150) and I've generally declined to "fix" issues in the form of "users with access to no spaces can't do <something>".

It's possible that changes in T13024 may have fixed some of these issues, but this was a happy accident if they did, not an intended change.

That said, I'm slightly more sympathetic to "can not log out" than to the other flavors of this.