USI/MKS - Part Listing Errror

[LegoF4]

I am running a (somewhat) modded build, including USI Kolonisation Systems version 0.2.4, on KSP 1.1.3 (64-Bit). In both career and sandbox, many parts are missing from the VAB/SPH listings. These parts do appear (and can be sub-purchased in) the CTT, however there is some error whereby these parts cannot be listed in the VAB - I attempted to add them to a category manually, with the following custom category:

CUSTOM_PARTLIST_CATEGORY

{
    categoryName = Missing Parts
    icon = stockIcon_bulkheadprofile
    SUBCATEGORY
    {
        categoryName = ISRU
        icon = R&D_node_icon_specializedcontrol
        PARTS
        {
            part = MKS_Drill_01
            part = MKS_Drill_02
            part = MKS_Drill_03
            part = ScanOMatic
            part = MKS_Antenna
            part = 
            part = 
            part =         
    }
    
    SUBCATEGORY
    {
        categoryName = Structural
        icon = R&D_node_icon_specializedcontrol
        PARTS
        {
            part = MKS_ExpandoTube2
            part = MKS_ExpandoTube4
            part = MKS_ExpandoTube8
            part = OKS_Tube
            part = OKS_Tube_Lg
            part = MKS_FlexOTube
            part = MKS_RigidTube
            part = MKS_DockingPort
            part = OKS_HabRing
            part = OKS_ColonyHub
            part = OKS_AgModule
            part = OKS_Aeroponics
            part = OKS_LgHub
            part = OKS_Storage_ILM
            part = OKS_Workshop
            part = OKS_Workspace
        }
    }
} 

The parts did not show in the custom tab, nor the normal tabs (including the USI one) nor on the search bar. All mods were installed manually, tell me if you need  logs. If you need any more info, please tell me, otherwise I hope someone knows of a solution! (Or could be I'm just an idiot.... take your pick, just tell me the solution anyway)