Have you tried syncing your chrome to an account, and doing a wipe/fresh install? Perhaps the sync data is bad and it might be good to get a fresh sync going on a new account. As you stated, the culprit was likely the experimental settings in about:flags which makes sense.
Writing an extension for Google Chrome is not always an easy task and you'll likely run into some problems.
Update The Google Chrome Extensions To Make Them Work Again.
Google Chrome Forums Google Chrome OS Google Chrome Themes Google Chrome Plugins and News.
i have an extension that worked completely fine when i integrated it into my google chrome web browser from "chrome web store" using "add to chrome" button.
Finally the solution was to delete and re-install all extension. They all work fine now.
Integrating with DevTools & Chrome. DevTools Extensions API.
If it’s not working Then? Contact extension factory them through contact us page hope they will help.
Quite impressively, Google Chrome has a collection of extensions.
So without further ado, here is a step by step tutorial on how to fix the Chrome Extension on any version of Google Chrome if it stops working/functioning