Edit This is now fixed. If you keep getting errors, clear your cookies for the stie.
For the past couple of days I have been unable to login using solid.community as an IDP and several other users have reported the same. We get a 500 server error in the popupup from chrome and firefox from desktop and android and from a command line script. Oddly enough, I can login if I go to the register page and use its login button. And oddly enough, other users have reported they can login the regular way with no problems.
At a higher level : who is in charge of the solid.community server and whom should we contact in cases like this?