I have been using reverse auth in my Twitter app for a year now. This morning my app reverse auth stopped working. After doing some inspecting, I found out that I am receiving an error message that states "Reverse auth credentials are invalid." This is extremely confusing to me, as I have changed nothing. I have emailed Twitter but haven't heard back yet.
Any help would be greatly appreciated!
We just noticed a similar issue in our app. Unfortunately the documentation is no longer accessible.
Changing the HTTP method of the initial https://api.twitter.com/oauth/request_token request from GET to POST fixed it for us.