Can' enable collisions

Hi
I’ve been importing meshes from maya (obj extensions) but now the auto generate collisions box is unchecked and grayed out, and I can’t do anything about it.
So my meshes don’t have any collisions, what do I do ?

Here is a screenshot of the auto generate collision box, I can’t check it.

try to import as fbx please

I did it, didn’t work either :confused:

i am really sorry for late response but do U know this that U can create a collision mesh separately inside a modelling software like blender or maya

https://www.youtube.com/watch?v=TTsAYpqHU-c

this is for 3ds Max and maya
https://www.youtube.com/watch?v=uXGW6Vf2rzY

https://www.youtube.com/watch?v=hLnmkOqJAZg

Okay so I’ve been following your ideas and I’ve made custom meshes for all of my meshes and export them to .fbx
It now works perfectly. Thank you all !

no problem man just have fun with UE4 .