My Google Chrome extensions have all stopped working
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. Hard to always see the far-reaching impact changes there might have. Odd that it affected all extensions though.
I was facing the same issue. Here is what I did to solve it:
Close the Google Chrome browser
Go to task manager and do "end task" wherever you see "Google Chrome"
That's it. Restart the browser and everything should work properly again.
If this solution is not working for you then disable the extensions, then follow the step 1 and 2, and re-enable the extensions again.
I also faced same issue after my computer has shut down unexpectedly. When I restarted my computer, my Chrome extensions, bookmarks, history, cookies etc. stopped working.
I think root cause was that my user profile was corrupted. So i followed steps mentioned in the below link to create new user profile. One important step to remember is that do not forget to take back-up of old Default folder as mentioned in the steps in below link.
https://support.google.com/chrome/answer/142059?hl=en
Now here comes the trick. I open the browser which created new Default profile and hence all my previous settings were gone. I was worried. I did not wanted to install all extensions again and restore my bookmarks again. So i did the trick.
I closed the browser. I went back to same folder where new Default folder was created. Then I renamed this new folder to "Default - New". And i copied the old corrupted Default folder back again.
To my surprise when I opened Chrome browser, it asked me to Restore the chrome and clicking the button within a second everything was fine. That's trick saved me and so i thought of sharing with other.