Twitter Login for RSVP

i was trying to trying to implement the OAuth for the RSVP in the Events + Plugin, but unfortunately i always get an Error if I try to log me in.
You can try it for yourself:
. Click on the Button: "I'm Attending" and then on: "Login with Twitter". Then there should be an new Window with the Error.

I also tried to follow the Steps described in the Steps ( -> USAGE) but unfortunately the Manual is outdated in the Part of the Twitter Apps. So the Steps could´t all be completed...

Best Regards