I think I have narrowed the problem down to lines 3-15 in the arabic translation:
https://github.com/Jermolene/TiddlyWiki5/blob/master/languages/ar-PS/ControlPanel.multids#L3 To reproduce the problem using just the core: node tiddlywiki.js editions/pluginlibrary/ --build library -- You received this message because you are subscribed to the Google Groups "TiddlyWikiDev" group. To unsubscribe from this group and stop receiving emails from it, send an email to tiddlywikidev+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/tiddlywikidev/bb2f558e-5daa-4f18-8dca-73abc61d4dbfn%40googlegroups.com.
