Mike Weber 2 years ago I'm integrating Vimeo with my company's C# web forms website and I'm facing an issue during the authorization phase. I'm using the DotNetOpenAuth library in the exact fashion as the sample project. My code works fine with the Twitter API when I replace the consumer key/secret and ServiceProviderDescription URLs (access_token, request_token,a nd authorize). Here is my test web form for Vimeo: gist.github.com/weberwithoneb/c6aeecf5f9eef2628f96 After loading the page redirects to Vimeo for login. I login as the same account that owns the application (a PRO account), and then I get this error: >> Uh oh, something went wrong! >> It looks like we're missing some required info, or the info you submitted was invalid. If you go back to the previous page and try again, it may work. If you receive this message again, please contact the app developer. Does this sound like I have misconfigured the application in on developer.vimeo.com? Notice anything strange in my code? Thanks!