The latest update to Trello update has broken TrelloX. I'm aware of it, and expect to have a fix late next week (before 29-March). I apologise for the inconvenience.
Unfortunately this isn't a simple problem, in that it will require me hunting for the cause, and re-architecting part of how TrelloX works.
The good news is, that's no problem. It's just a question of time...
On first inspection, it looks like when TrelloX is enabled, the Trello Board isn't completely loading for some reason. At first I thought this may be a conflict of jQuery versions (because Trello uses really old versions of jQuery and jQuery-UI—I use the newest versions possible that don't have conflicts). However downgrading TrelloX's jQuery to the same versions Trello uses didn't help.
I suspect the problem is with a library TrelloX uses called mutation-summary, which watches for changes to the DOM, and lets TrelloX know something's changed. The other part of the story is the new version of Trello seems to be throwing some weird (and also malformed) errors in the console.log about cross-frame security issues.
In any case, I need to diagnose the problem, however my focus is on Licorice right now, so it will be a week until I can properly look at TrelloX. Once I've found the problem, it usually isn't difficult to fix.
If you have any ideas, please let me know! Most of the time with these things is in finding the problem.
Thank you for your patience, I'll post again when it's fixed.