I'm making a map with a new cube, with env_explosion and physexplosion. I used a regular prop_floor_button with a trigger on it for my prop_physics to work on it. Eventually, I had to change it to a cube button for the puzzle, but when my cube exploded while touching the button, it crashed the game. I tried changing the trigger brush and the button with new ones, and the same thing happened, except for when the cube was touching the trigger (it was too big apparently), but not the button.

I had a similar problem in this map http://steamcommunity.com/sharedfiles/f ... =892858669
The fact is the game crash when a cube (or something physic) disappears into a trigger.
The solution for you is to avoid to use triggers for your buttons:
Use prop_weighed_cube et change the model using scripts or the console.
Always avoid to use prop_physics when you can do otherwise