facebook users are not added + window appear and disappear quickly

There's a few reasons that could be happening, but we'll need a little more information to help you diagnose it. Can you let us know the exact version of Joomla and JFBConnect you are using? Also, if you can, please let us know what URL you are testing on so that we can see what's happening. That will help us diagnose things a little better.

Finally, please post from the account you subscribed to JFBConnect from. Priority support is for subscribers only.

Thanks,
Alex

RTL shouldn't be a problem. Again though, can you provide the information asked for above?

Specifically:
* Your Joomla version
* A URL this is happening on so we can see the issue.
* And, the account that you subscribed to JFBConnect with.

Thanks,
Alex