Ok here is what I can recommend then you need to unsubscribe to all workshop mods and then uninstall ns2 and then reinstall. Then connect to the server and it should work fine. It also might after you unsubscribe and manually uninstall all workshop mods from you system.

the issue appears to be caused by some file corruption in the extra entities mod that combat uses. Your local copy appears to have some file corruption that is causing the issue.