See File:TwoColumnBug2.png; it seems that the help text above the right column has disappeared, and thus the columns become unaligned. Not sure if this is the intended behaviour or not, but I assume the two boxes should always be aligned.
Topic on Help talk:Paragraph-based Edit Conflict Interface
Misaligned boxes due to help text disappearing
A fix for this is deployed now and the issue should be gone. Thanks everyone for reporting and investigating!
This is not an intended behaviour, thanks for reporting! I created an issue on phabricator
@Samwalton9 we have problems of getting this error ouselves, but looking at the screenshots it seems that you have a gadget installed that works on the page, too. Could you tell us what it is, so we can check that? Thanks!
I have the following gadgets enabled which may be affecting this: Twinkle, Syntax highlighter, refToolbar, and MoreMenu.
From a little more testing it doesn't happen every time. I just did 2 successfully and then had 2 where it happened.
@Samwalton9 We've tried with the Gadgets you've mentioned enabled (except Twinkle which we couldn't enable) but we couldn't reproduce the error. Is there a chance you could try to disable your Gadgets and see if you can still reproduce the error? Also, can you give us some information which browser you're using? Thanks!
Just tested it with a fresh account (no gadgets enabled) and had the same issue on the 2nd edit conflict test. I'm using Google Chrome, version 58.0.3029.96; only extension I had enabled is uBlock Origin, but from checking the logs that didn't block anything.
Ok, we finally detected a few flaws in the code under certain circumstances that might cause the issue you're describing. We've fixed these issues in https://gerrit.wikimedia.org/r/#/c/353535/but the code will not be deployed until the beginning of next week unfortunately.
Thanks again for reporting and providing all necessary information for us, we hope that the issue will be fixed once the new code is deployed.