Checked "Require a password reset on next login" on my account, can't log in anymore As a test, I checked the "Require a password reset on next login" box for my account and then logged out.

I tried logging in, expecting some sort of password reset screen, but nothing happened.

I then tried to reset my password at the login screen -- something I was able to do before -- and nothing happened.

In both cases, I get a "500 (Internal Server Error)" in the console.

Any ideas for fixing this? At the very least, can I just reset my password directly in the DB via phpMyAdmin?

FWIW, I also ran into this problem using a Craft demo site.
On your local installation if your check the "Password Reset Required" button for a user and you get a 500 Internal Server Error the next time that users logs in, there is about a 99% chance that email isn't configured/installed correctly on your server.

You can verify this by checking the craft/storage/runtime/logs files for the underlying error message.

Craft's email settings are managed under Settings->Email in the control panel.

When you tested on http://demo.buildwithcraft.com and saw the same behavior, that's because we specifically disabled all email functionality on the demo sites in order to prevent them from turning into SPAM relays.