I decided to hop on a server with a friend to teach him PAC. While he was joining, I chose to mess around with some SWEPs just to pass the time.

I hold down Mouse1, and instead of bullets and smoke coming out, I see a flurry of red blinding my screen. As soon as it fades, I see Red X's flying away, and dissapearing.

I check the console to see what the problem is, and I find this;
Attemped to precache unknown particle system "swb_rifle_med"!

I've tried uninstalling and reinstalling the addon, verifying intergrity and what not, and I still have the issue. Note that this doesn't happen when I put on a silencer, and happens for Here Goes Nothin', as well as BER's Random Stuff. No other CW 2.0 weapons do this besides Hotline Miami 2.0 SWEPs.