I also ran into a problem once where the clozure was inserted with the closing brackets before the opening brackets (e.g., “}}{{c4::”) but I haven’t been able to replicate it to get a screenshot or a description of how to reproduce it.
Another problem with editing MathJax in the new editor: If you copy and paste a section of text containing a MathJax equation, then the output is often mangled (but not always).
@dae, I’ve just upgraded to version 2.1.54 (b6a7760c) and tested all of the problems I listed above. They all appear to be problems with the new version. The problem with cutting and pasting is somewhat different. The output isn’t quite so mangled, but it’s still not correct.