I second that. I am experiencing the same issue. I use the GENTOOL option, as the launcher did not work for me. I have tried all the suggestions in the "common issues" post without any luck.
If I enter a wrong email I get a "email invalid message", if enter a wrong password, I get "wrong password" message. Only if I enter the correct credentials - I get the error message described by Sir Best.
Using the ultimate edition from origin - lauching the game without origin
I am signed in to C&C online while trying
Windows7 64 bit /A friend of mine has the exact same issue on winwos 10
we'd love to play Generals, please help