In Meta, the following internal error can be seen when navigating pages or performing actions: "Fatal exception of type "LogicException"". This error seems to appear at random (if you refresh enough times, it might let you through), and can even appear while using OAuth to login to Phabricator. I was able to trigger this when accessing Special:RecentChanges, Special:Random and Agent Isai's talkpage. I do not know if other wikis or other pages on Meta are affected, though it is very likely.
Description
Event Timeline
Can't reproduce so it must be an individual issue. Please try the following:
Open the private browsing mode of your web browser and login, and go to Special:UserLogout. Next, open the regular browsing mode of your web browser, delete your cookies for *.miraheze.org and try and login again
Looks like it was solved, as I too am unable to trigger it anymore. It's not an individual issue as that is a server-side error, and the cache doesn't apply as MediaWiki tells your browser to ignore the cache when logged in. I could trigger this both logged-in and out.
Correction: I mentioned the cache because I once again didn't read people's messages fully before responding. Cookies are unlikely to be the reason, as that happened on a new browser session (my browser clears cookies on exit).
Just remembered I took a screenshot of it, I should've shared it when creating this.{F1939471}