You can refer this thread for same issue:

https://community.ringcentral.com/questions/89791/my-case-portal-login-error.html

I'm getting the same error still after clearing cache and cookies. Get the salesforce error when I hit Try Again. @Jessica-Community_Moderator please refresh my account if possible. It's been broken for several months now.

Hi, I'm facing the same issue. Could you do what ever you did for the other then I will clear cash and cookies and try it myself again

I've been getting this same error since last Friday. I'm trying to sign in using Google, as I've always done, but it does the same thing if I try logging in using my phone number + password.

I've tried clearing browser data, no change.

I am also receiving the same error message. Tried four different browsers but getting the same error.

I'm having this issue and have tried different browsers and deleting cache/cookies and restarting the browser but the problem continues. How can I get this issue resolved?