Well then, I got got better just in time then...
Server was responding fine, but restarted anyway.
Hey, feeling minecrafty again....looks like I need to be whitelisted. hunternclark
Thanks for the timely response, good to hear you've gotten better, never fun being ill of course.
I was only just now able to test but I'm still hit with the same error. Not quite sure what the cause is, I haven't made any changes to the game or computer settings that could've triggered it. I've also checked this on all devices which I've played on the server with within the past weeks and they all cough up the same error.
On the new version, turns out 1.12.2 is just a bug fix, so no need for updating to that version. The upcoming 1.13 might be an actual content patch.
On that note, I tried that new version just in case but still exact same error.