When trying to authenticate with OAuth, an error similar to the following is seen:
"Failed to authenticate user using OAuth2/Open ID Connect. VI.Base.ViException: Claim 'mailnickname' was not found."
In the configuration for the OAuth connection in Designer, under the "Object properties", the value "Search settings" must exactly match the claims you are using. In the example above, the value provided in the "Search settings" is "emailaddress", but the schema contains "email", not "emailaddress". Inputting the correct claim name resolves the error.