Welcome to the RingCentral Community

We are having an interesting issue where our program is unable to authenticate against the RingCentral API. I can use the same credentials within postman and it works fine. But when our program attempts to authenticate, it has lately been giving "error":"invalid_client" errors. I've double checked the client ID, client secret and JWT. It worked once and then all of a sudden is stopped working even though I could successfully use postman.

We previously had a bunch of errors come through so we turned off the app and then were fixing the problem. We turned the app back on and it works through postman but not through the program. Any ideas?