/questions/ask/ returns 404 error after installation!

dear all

I've just purchased, installed and configured your plugin.
I don't understand what is going on http://timelapseitalia.com/questions/ask/

The antispam and your plugin are installed and active. Few categories already set, and nothing won't show up. I'm going on vacation in 2 days and I purchased the 30days membership, therefore I'd like to solve this at your earliest convenience.

My best regards,
Marco