[sugarinventory] addons/sugarinventory/lua/sugarinv/client/cl_inventory.lua:168: attempt to index a nil value
1. AddToBuyer - addons/sugarinventory/lua/sugarinv/client/cl_inventory.lua:168
2. DragMouseRelease - addons/sugarinventory/lua/sugarinv/client/cl_inv_pnl_derma.lua:667
3. unknown - lua/vgui/dlabel.lua:206
The LUA error