Ok, so I went to my arma 3 folder to view all of the mods. I opened the @AllInArmATerrainPack's folder, inside it was a folder with the exact same name . Inside the second allinarma folder, were all the folders/files "addons, dta" etc. So I cut it then copied it over the previous one and it worked. Not sure if my problem is the same as yours, but I hope this helps.