Errors in GMOD server & Additional Problems

So I am trying, run this gmod server me and my friend are trying to build, and there are these errors i dont recongize, saying that it can’t create a physics object for a certain item like ERROR!: Can’t create physics object for models/props/cs_militia/axe.mdl
What is this and hwo can i fix it.

The second one is that we have lag on the server everyone gets about 230-ping on the server and i think it’s due to these errors. Please help and im new to coding so i will need step my step instructions plz!

Thanks
Lecota

Do you have CS:S mounted to the server?