Random Errors, Need help asap! :)

I keep getting these errors in console. Anyone know what else to do? I only added Gemstone Printers Beta and added it into the entities, then this shit happens.

You are using Garry’s Mod 12 addons in Garry’s Mod 13.

I used the same addon on different server’s and they worked just fine.

Go to line 13 of that addon and replace the words ‘ValidEntity’ with ‘IsValid’.
As Robotboy655 said, this IS a Garry’s Mod 12 addon and the function ‘ValidEntity’ was removed from Garry’s Mod. Perhaps you’re not using the post up-to-date version of the addon or something.

Sorry for late reply. I will try that now. Thanks!