Friend and i have same addons but on Coop server he sees error signs??

[DaOrangeGamer]

Hi all! So i desperately need help with this issue me and my friends are having. We went through all the addons in the main menu together and downloaded the ones we want at the same time. However when we join a server by using hamachi or Evolve as we use, the one who isnt the host sees error signs everywhere! Even though we have the same addons.

Please help, this issue is very frustrating now as no addons will work !