Custom content packing and cubemaps wont work in SFM

The Siphon

L6: Sharp Member
Mar 2, 2015
278
190
I was porting my detail contest map to the SFM workshop, I tested the map in SFM and all custom content was missing and the cubemaps were just rainbow colored spots.

I packed the content with VIDE and built HDR cubemaps before that. I have no idea why that happens.
Any ideas how to fix this? Thank you.