How are any other mods you're installing on your game? Did the installation work correctly for them?
(to me, "got the .exe and the .tp2 in the BG2 folder" sounds unfamiliar, because usually you just unpack the whole mod into the folder with chitin.key, and that includes deArnise directory, too)
I'm using the enhanced edition from Steam, got the .exe and .tp2 in the BG2 folder and have started to run the installer only to get the message that it failed ERROR Installing [UNDEFINED STRING: @0] stuffstuffstuff ERROR: Failure("ERROR: cahrsets were not converted because iconv could not be found in deArnise/iconv")
I am guessing there is something I am missing, but am really out of my depth here and don't want to damage my game. Any advice (with instructions or details please) would be really helpfull.