Linkedin Oauth2 Authorization Server Encountered An Unexpected Condition

We're getting this weird error for some of our users who are trying to authenticate via linked in OAuth2 API from mobile within a webview. https://www.linkedin.com/uas/oauth2/autho

Solution 1:

We were able to reproduce this error when a space character is added before or after the user's email address on the LinkedIn authorization form. LinkedIn doesn't do any trimming of extraneous whitespace on this field.

My hypothesis is that this happens on mobile when people use the space bar as a way to accept an autocompletion recommendation on the email address. So the user starts typing their email address, the OS recommends a known email address and, generally, mobile OSs will use the recommendation when the space bar is pressed.

Solution 2:

I had this exact problem. In my case, the problem was that I was overriding the default authorization scope (using ?scope=..). I'm not sure why this caused the problem, or why it always happened to mobile users. But removing the override made it go away.