Thanks for the update. Sorry for not realizing this earlier, but somehow I believed that I was running 10.12.4, but I was in fact running 10.12.3.
I did some debugging, and, while there is no problem with FoldingText loading on 10.12.4, there is indeed a problem with 10.12.4 and the jmk_plugin.
I've also been able to debug the problem that's coming up in the jmk_panel plugin, which is basically how it uses the DOM method
insertBefore takes two arguments, an element to be inserted, and a reference element, before which the new element should be inserted, the
You can resolve the issue by removing the plugin.
For people who like to keep the plugin, you can find any instances of
insertBefore in the jmk_panel code and fix it. For example:
document.body.insertBefore( this.element ); to
document.body.insertBefore( this.element, null );
Note that I only added
, null within the parameters. That's all you have to do with any other instances you find in the code.
Meanwhile, I've made a quick-fix for FoldingText to allow you to load it without plugins if it encounters a similar issue. Going to test it a bit more and release a dev-version soon with the fix.
Hope this helps.