Problems with the Game I have a question

Alright so I have been playing gmod and its pretty cool but there is one problem on one of the roleplaying servers it actually happens on all of the roleplaying servers but anyway whenever I am a computer tech I can see and build everything but when I buy the speaker I cant see the speaker I just see a giant ERROR but I can still wire the ERROR (speaker) to the computer and play music but I cant move it without it flipping out and I cant weld it to anything… So I was just wondering if anyone knew anything about my problem please post THANKS! And if there was a way to fix the problem.

You don’t have the model for the speaker