I have successfully implemented google authentication of oauth in redirect mode in my web application s couple of months ago and it was working till today. Today I logged out from my application and tried to log in again with google. As a result I received error: Error 400: redirect_uri_mismatch Request details: redirect_uri=https://wroolo.com/__/auth/handler flowName=GeneralOAuthFlow And sometimes I get this error: Request details: response_type=code redirect_uri=https://wroolo.com/__/auth/handler state=AMbdmDkvtq5fK7dsANuqJ57yjWt5JiWSuwnng_2hrYLxGZBraW1lJSGRBwg0WU4UjK2LY6v9IebZ0CqR5ySUwXnNaTVKS5keZTjuGLXNzdwwec3RnDKuSoW8Nkk-oC6kVSbSGTx0ieUzkHY_VQiMJfmM0MwJZM2YOObRGpxJtbsZ67b8X_3nFOX7Q12dCBtWN6OClGTpenY5OtF0V9Oc0bODtfzPrVDwIbzpiOqE_9fak11vUNgj9WkU-_ouUHU4UF6GyP-aFawP8vC0LZ1JTPeETxcPh25Ff68OYAFv2RrLu6b-SA client_id=166898159068-sda1qbim0eo3090aoc5k86nujm2abq4b.apps.googleusercontent.com context_uri=https://wroolo.com access_type=online scope=openid https://www.googleapis.com/auth/userinfo.email https://www.googleapis.com/auth/userinfo.profile flowName=GeneralOAuthFlow I checked and It still works fine with my other web applications. I read dozens of posts on stackoverflow, reddit and google community. I added plenty of uris in cloud console. !google cloud console (https://i.sstatic.net/0b2jRl3C.png) Everything is green on my project checkup dashboard. [!project checkup status1]1 Have you met such behaviour, i.e. working fine for a couple of months and suddenly problems? And I have just checked it works fine on safari on the same computer, it doesn't work on chrome (I upgraded chrome to recent version). Continue reading...