I created an application in C# for retrieving mentions from my own account following the single-user oAuth documentation. This has been working great for more than a year now. However recently it started returning not authorized errors for no reason I can see. I tried creating a new application on my account with permission to read, write and direct messages and generated new access tokens, but the problem persists. I left it a couple of days then checked the permissions and tokens to make sure twitter had updated my settings properly but it made no difference. I create the following url in my application to post using the WebRequest method in C#(Keys are fake of course).
Can anyone tell me if I am missing anything from the url, or whether anything has changed in the twitter API regarding authorization or mentions. I am pulling my hair out trying to figure out what’s wrong, any help will be appreciated.