In Firefox browser, when editing extension (see screenshot) an error message appears in the top right corner of the screen of the GUI.
The error only appears when clicking the edit button within 2 seconds after launching the previous screen, which is the Applications/extensions overview screen.
When waiting a few seconds between launch of Applications/extensions and editing an individual extension, the error does not appear.
In chrome the error is not appearing.
Forgot to mention that the error /error message does not seem to have any real impact on functionality in Freepbx GUI nor on managed system.
firefox version 53.0, 32bit
freepbx version FreePBX 126.96.36.199
What happens is you cancel a request mid request and it causes an error. There is an error handler that shows all errors via toast messages. I guess it is a matter of catching those but they may be the same as a 500 response which we want to show