While playing, the arm model of my character became invisible. I think it happend after I switch to grenades and back (not sure tho).
Could only be fixed by changing class. Only resupplying wouldn't fix it. Only respawning wouldn't fix it either.
Happend in Coop on Summit Security Side.
I also noticed that switching from your first weapon to grenades and back quickly would sometimes result in still having the grenade shown in your hand but on the HUD you were back at your primary weapon.