Hi Wizard, thank you for your help! I can confirm this solution worked for me.
I had that same Dta folder on \Arma 3\Heli\ but I don't remember moving any of the files on my ArmA 3 folder so I don't know how it could've gotten there. Anyway, I removed that Dta folder from the Heli folder and both the original Launcher and Arma3Sync seem to be working good again.
Thanks again for your time and help; have a nice day!