I've been getting variations of that almost since I got here. Also the site returned an unkown error at one point and was extrememly laggy. So no I don't believe it's you or me but the site itself that's having problems.

There's a thread up in Problems & Bugs about it. It's happening all over the site (to everyone)

Thank you! Phew! Okay, thank you! I was like, what the heck is going on?? Lol. Thanks :)

this is an expected part of some site updates that will be taking place, as explained in this thread - 👋 Server updates!

and here is the thread for listing any of these warnings you find around the site - PHP Warning list - READ FIRST POST

i recommend joining the site update group to receive notifications about stuff like this so you're not caught off guard :P

thanks so much! I did see an admin post by Keith about it too :) it was just alarming, it happened out of nowhere and I hadn’t read anything about it. And Subeta was being suuuuper laggy on top of it!

yeah sometimes these things pop up before the announcement anyway ¯(ツ)/¯