Weird "The popup was closed" error

oauth
error-codes

#1

Hey, this is driving me nuts…

I have set up an app and a test with the “Try OAuth” on oauth.io it indicates success half of the time and half of the time it returns the following error “The popup was closed”!? On a test-site I have this error shows up every time. Also the pop-up opens and then closes very quickly.

Any hints very much appreciated

bets regards