"X"key Folding isn't working

[Valentinootje]

Can someone help me with the "foldable" options, I can't get it to work...it only works in older versions of the game, but not in the new patch.
Do I have to update something..??!
My hooklift works perfect in the older patches, but the fold/unfold option doesn't work in the new one... I just copied the hooklift XML text from a working hooklift truck, and it works perfect in older patches (1.1 - 1.2 etc.) but not in 1.4