I think all of you use AVG scanner (there were some more I've investigated this).
It will mark Ragnarok Online executables as trojans and it will constantly try to delete/heal/put it in quarantine.
Run your virusscanner once, it will remove it, redownload just the executables (will upload later for people who don't know how or where)
and then download this again, extract this in your Forsaken RO folder and it should work again.
Your option for now is either turn your Virus Scanner off(which is bad), or get a new one temporary.
This has been reported to AVG (and other companies) already and it will be fixed as soon as possible.