Missing Default knives, and Mutation Mode Bug

So I have just played some games of HMX to realise that my default knives, or any knives do not load in. Also when I am mutated or selected as the mutant, I am given my own gun, but unable to attack. When I am killed as a mutant, the gun goes away, displaying the normal Mutant Fists, however I am unable to attack. What is the problem, and how do I have fix this?