If you are having a big investment of models then you might consider to remain on Poser 11 or bellow. There are several reasons, Python combability loss due the upgrade on Poser 12, this will cause that many packages you own and have Python Extension will no longer work correctly, allot of creators were using these for Materials and Morphs. Allot of these Packages are really great and would be of no use in Poser 12.  So if you are a Proud owner of Surreality Packages all or most of these would not work and this is just one of many Artists creations. also most lululee creations would be affected. No need to build up a list as it is Huuge!

The other thing is is that Poser 12 is still on Pre Release . If you would be a New user that just goes for the latest La Femme Products then it could be considered to go for Poser 12 with the restriction to skip older sold products avoiding in desiderable conflicts.

The only one known who is having the Know How that i am aware of would be Summoner aka "Gate". He has a very effective weight map technology for poser in combination with external Programs. But I doubt  he would cooperate or share the knowledge after the discriminating acts of Rendo.  

the whole model seems to be out of shape :( 

I guess you would get best results by using the "Collada" export from Poser rather then to use FBX. I Believe that it would work out using Collada in your case!

Adding:

Make sure you export the Collada Including the UV Textures else it will not work

Poser 11 should  generate the Alpha maps automatically if your import file is set up correctly with the Alpha cannels . In most cases it should work.

for a Environment that might be complex with allot of alpha maps you normally would import it as Fbx or Obj , to enable poser to generate these Alpha maps in the texture folder you just need to save a Collada version of your model in the 3D program you are using, make sure the alpha and trans are on before saving. Now import that collada file into Poser, you will now see that all the Alpha jpg maps have been generated ( Extracted from the Png ) in the folder you imported the model. you now can trash that colloda version ( In case it is just a Prop > Static , if a Articulated Figure Keep Collada ) now load your Obj version and apply the needed Alpha maps to its corresponding material zones. this is the most efficient way generating clean alpha maps out of the Png files! 

This a was a working function in Poser 11.1 not sure if it is still working in Poser 11.3 or 12

I am not sure if there is the need to explain all the technical stuff , the error is getting generated due the parts not merged in the figure

to make it short here is a download link of the fixed model for you that works in poser Fbx and Collada the collada version is adapted so it will be  the better choice to load into Poser  both are working just that the Fbx will need the textures to be adapted and it loads on x -90 degree so try Collada first.

DOWNLOAD

Quiet simple, If you own Poser 11 pro from Smith micro or a Prior version like Poser 2014 just copy the needed python to the Poser 11 Bondware version and it should be working again. Else try asking someone you know to send you the files. Actually it should of remained a option in Poser 11as it was a part of it when originally purchased. Have no Idea why Bondware removed this option with many others.