Lua error when opening inventory

[Naehiro]

Whenever the inventory shows up, I am presented with this error:
addons/pointshop2/lua/ps2/shared/sh_0_pointshop2.lua:213: attempt to concatenate local 'port' (a nil value)

1. CalculateServerHash - addons/pointshop2/lua/ps2/shared/sh_0_pointshop2.lua:213
2. loadItems - addons/pointshop2/lua/kinv/client/cl_ditemscontainer.lua:106
3. unknown - addons/pointshop2/lua/kinv/client/cl_ditemscontainer.lua:72
   Is this because I'm trying to use the addon on a single-player server?