Fix "Message not delivered" in Hangouts on Chrome : Message not getting sent from Hangouts in Chrome

Fix “Message not delivered” in Hangouts on Chrome : Message not getting sent from Hangouts in Chrome

I was very frustrated when I was unable to send messages through Hangouts from my Chrome browser. I tried everything possible including:

1. CTRL + SHFT + R
2. Signing out and signing back in to Google.
3. Restarting my browser.
4. Restarting my system.
5. In-cognito.

However, none of the above options seemed to work. Finally, I disabled all my extensions and tried again, Hangouts worked!So, in order to figure out which extension was causing the issue, I enabled them one by one and tried Hangouts after enabling each.

The conclusion

It was not the extension itself which was causing the issue but it was related to what extension did. The extension which was causing the issue was – Allow-Control-Allow-Origin: * (Link). This extension is used to allow cross origin access, which is by default blocked in browsers for security concerns. I just disabled CORS, I did NOT remove the extension itself, and tried again, Hangouts worked absolutely fine!