I have followed all the directions, like this:  

https://help.salesforce.com/apex/HTViewSolution?id=000004931&language=en_US
https://developer.salesforce.com/forums/?id=906F00000008kFmIAI

... you get my point.  

When I change the Server Host to https://test.salesforce.com then go to the OAuth sign in and click sandbox I get the following error message:  error=redirect_uri_mismatch&error_description=redirect_uri%20must%20match%20configuration

Therefore I tried the "Password Authentication" and put in my username/password (it still says https://test.salesforce.com in the Salesforce Login URL:)  

Thoughts? I've tried googling this issue and haven't seen anyone else encounter it.  If it means anything when I go back into settings, it will say "https://login.salesforce.com" if I do the exact process I outlined before.

Thanks - Sean
 

I have followed all the directions, like this:  

https://help.salesforce.com/apex/HTViewSolution?id=000004931&language=en_US
https://developer.salesforce.com/forums/?id=906F00000008kFmIAI

... you get my point.  

When I change the Server Host to https://test.salesforce.com then go to the OAuth sign in and click sandbox I get the following error message:  error=redirect_uri_mismatch&error_description=redirect_uri%20must%20match%20configuration

Therefore I tried the "Password Authentication" and put in my username/password (it still says https://test.salesforce.com in the Salesforce Login URL:)  

Thoughts? I've tried googling this issue and haven't seen anyone else encounter it.  If it means anything when I go back into settings, it will say "https://login.salesforce.com" if I do the exact process I outlined before.

Thanks - Sean