Britalian

I was getting this error, too. So, I changed it to get the oAuth token and pass that to ENSession using SetSharedSessionDeveloperToken, as follows: var oAuth = new EvernoteOAuthNet.EvernoteOAuth(EvernoteOAuthNet.EvernoteOAuth.HostService.Production, "Key", "Secret", true); var errorResponse = oAuth.Authorize(); if (!errorResponse.IsNullOrEmpty()) { ENSession.SetSharedSessionDeveloperToken(oAuth.Token, oAuth.NoteStoreUrl); } That seems to work for me.