I fixed it by going into my account, hitting edit, and clicking the save button. I think there’s a bug with the expiring session not being handled. And clicking save seems to log you back in.
You somehow dodged a bullet, or recently reauthenticated. A great many people had their apps stuck in a wonky state because many instances logged everyone out after last night’s hack.
You don’t need to delete the app, but you do need to re-log in to be able to vote or comment (presumably because of the hack yesterday).
Go to accounts tab, and delete your account (from the list of logged in accounts) and then log back in. You may need to “add it” a second time before you can delete it.
I couldn’t figure out how to log out of the app. After the admins logged everyone out after the zero-day, I expect it left the login tokens kind of messed up. Uninstalling and reinstalling fixed it all.
I had similar issues, so I deleted the App and reinstalled and also changed my password. Everything is working properly now and with the Dev updates, it is better than ever!