I am going to this url (with id and secrets changed):

https://login.salesforce.com/services/oauth2/authorize?response_type=code&client_id=XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX&client_secret=999999999999999999999&scope=full%20refresh_token&redirect_uri=https://dev.gcast.com.au/Core/Integration/IntegrationLogin.aspx&state=sfdc&prompt=login%20consent

And I get this error:

error=redirect_uri_mismatch&error_description=redirect_uri%20must%20match%20configuration

The callback url in my app is:

https://dev.gcast.com.au/Core/Integration/IntegrationLogin.aspx&state=sfdc&prompt=login%20consent

Can anybody see where I am going wrong?