First of all thanks for this great mod!
Now to the point: some people were already reporting that they can't attach cistern trailers to their trucks. I'm having the same issue but since I know how to use blender and scs blender tools I decided to "debug" this problem by myself. Not all truck are affected. I loaded 4 of them and so far only mercedes actros 2014 seems to be problematic. In this truck advanced coupling colision boxes (two of them) are rotated 180 degrees around global X axis and that's preventing proper hook points alignment. Unfortunately that's not all. In the cistern trailer like in any other of your trailers there is a colission box along the hook arm (or however it's called
. In the case of cistern trailer the box is a bit longer so it is also prevening proper hook points alignment (even if the adv. coupling cylinder passes between two collision boxes, the trailer arm collision box blocks futher movement). Yet another thing which is making it even worse is that the trailer hook point on the truck is moved a bit to the left.
Here are some screenshots from blender to ilustrate what I'm talking about:
On this first screenshot you can see actros 2014 and cistern trailer collision boxes (yellow dashed lines). Hook points are aligned and you can see the trailer is a bit off to the left. Also you can see that the trailer collision box is in impossible position.
btw. maybe you're aware of this but: placing adv. coupling cylinder like this inside another collision box is unnecessary because it's the box that will collide with the truck adv. coupling collision boxes.
On the second screenshot you can see actros 2014 and coolliner trailer collision boxes. Hook points are aligned like in the previos image. Here the trailer collision box is a bit shorter so it may be possible to attach this trailer.
Here is one of the trucks with rather correct collision boxes layout (iveco highway):
but still the hook point is moved a bit to the left.
Here is a video of me trying to attach this cistern trailer with mercedes actros 2014:https://www.youtube.com/watch?v=oeMeIvhP76A
You can of course fix this truck by simply rotating two collision boxes by 180 degrees around global X axis but maybe you would be interested in more decent solution I came up with
Here is how it looks:
As you can see I added two additional collision boxes on the top and bottom. I also changed trailer collision cylinder into collision sphere and moved it forward so the hook arm collision box no longer gets in the way. Finally the hook point is now properly aligned. This solution works really well as you can see in this video:https://youtu.be/vCo78Pb-HFg
I know it is quite a lot of work so I'm offering you my help. If you agree to this solution, I can do it for all trucks and trailers included in the mod and then send you changed intermediate files so you can convert them and release whenever you like. I'm really eager to help you because I like this mod very much and I remember having same issues some time age before I was able to do things in blender. I was a bit dissapointed that I had to disable adv. coupling. So let me fix those issues once and for all