When I deployed a provider hosted app, got following error:
Unknown User
Unable to determine your identity. Please try again by launching the app installed on your site.
And I debugged it found "string contextTokenString = TokenHelper.GetContextTokenFromRequest(httpRequest)"return value is null, it means hosted application cannot get SharePoint token. But I don't know why.
I tried several approaches, none worked!
Anybody can help me?
Yungfu
