Vidscreen01a.vmt Errors in Console

How do I get rid of these errors, I have looked all over google and couldnt find a solution.

I have the Cuffs handties and hand cuffs addon from GmodStore and it those errors I believe are causing a glitch where the cuff disappears at certain parts of the map I play on.

That error is not causing your glitch, but you can fix it by editing the material file to remove the syntax error.