[Dynamics]

What version of Fiesta are you running? This problem has been on the official forums once, here. It was solved by an update to their Fiesta.

It would seem x-trap gives this error when the game version does not match the current x-trap version's diagnostics. i.e. X-trap is looking for Fiesta version 1.1.0, but instead finds version 0.97, thus suspecting an "illegal" change (though it's just a wrong version) to the client and immediately terminates Fiesta followed by terminating itself. Perhaps your previous patch did not patch correctly. I do not know. This happens in Cabal and KnightOnline as well, both of which use X-trap. Generally the issue is solved by updating X-trap (which cannot be done in Fiesta) or re-applying client patches.

My solution is to update your Fiesta with the manual patch even if you seem to be using the most recent version of Fiesta (1.2.97), as it may have mispatched through the automatic update. Don't ask how, I'd be at a complete loss to answer that one. Manual patch link can be found here, kindly stickied by Spirit. Please do try this, and if it does work then report back to confirm the solution for the error code. If not, post again so we can continue investigating possibilities.