We have a web service used to authorize a connection between our application to QuickBooks Online. It has been working for two years with the last successful authorization on 2/28/17. New authorization attempts can sign in with Intuit okay but when they click on the button to connect to QuickBooks, they get an error, "We're sorry! We're experiencing some problems. Please try again later." The url displaying this error is something like, "https://appcenter.intuit.com/Connect/CompanySelection?oauth_token=qyprdVRQgReiMqcN2CZDW5U7nX2sz1iC2f4pYWbHuyY9JB". Any ideas how I might determine what quit working? Thank you.
Some additional information. The authorization/deauthorization process works okay with Sandbox companies and my developer's account.