APEX Cloth suddenly stopped working

Hey everyone, I followed this tutorial step by step (thank you, Scizz, btw) and got APEX Clothing to work in a simple curtain, but now I’ve made another and it doesn’t work at all.

Its just a simple standard courtain like the one in the tutorial, but inside unreal all I get when I import the APEX file is the “collision volumes” option under “clothing” (check the image below).


Does anyone know what I’m doing wrong? I’ve noticed that in details it says that all my verts are Rigid, but in they 3DS simulation they are moving. I’m pretty sure I did everything exactly the same way… may it be a bug with UE4 4.7.5?

I’m using 3DS MAX 2015 and the latest version of the PysX plugin.

Thanks a lot in advance!!