Welcome!

Reinstall the client, restart computer, hard reset router. If if the servers idk what else you could try except wait it out

Cheers aidden, thank you for the bots I use frequently ;) seems to have done the trick, I appreciate your insight

Nope, neither 3

I ran the client flawlessly for over two weeks until I started getting the "UTFDataFormatException" error. After googling around people suggested I hard reset my router, no fix. Run in admin mode, no fix. Uninstall/reinstall completely, no fix. However, after doing all of that, the error message...