As this video shows, various weapon projectiles get destroyed when they touch the bounding box of a solid object. Since the bounding box can be much larger than the object itself, this can cause gameplay issues.
The Wrap Assassin is even worse since it will collide with the bounding box of an animation.
Some might remember playing on an imp when suddenly a Scout using the Wrap Assassin hurts himself as he tries to throw the ball. This is because an animated prop_dynamic somewhere in the map was mistakenly set to Solid.
It seems that especially models that don't have a collision mesh cause huge problems. For instance, the grinder model from mvm_mannhatten was used on koth_hotgarbage and caused any wrap assassins on the entire map to explode instantly. The map set the grinder model to Solid. On the map mvm_mannhatten however, the model is set to have No Collision, which prevents the problem.
Recap:
Disable Collisions on any entity that does not need it, and especially prop_dynamics that don't have a collision mesh in the first place!
Bonus PSA:
Disable Bone Followers on prop_dynamics (unless it appears to break the animation). Bone Followers cause lag and increase the file sizes of demo recordings dramatically!
