NullRef spam at at USITools.ModuleResourceConverter_USI.PostProcess

[fat-lobyte]

Hi, I am having a problem with my save since switching to KSP 1.3.0. With my Base, I am getting a NullRef spam:

NullReferenceException: Object reference not set to an instance of an object
  at USITools.ModuleResourceConverter_USI.PostProcess (ConverterResults result, Double deltaTime) [0x0000a] in D:\Dropbox\USI-GIT\UmbraSpaceIndustries\USITools\USITools\ModuleResourceConverter_USI.cs:56 
  at BaseConverter.FixedUpdate () [0x00000] in <filename unknown>:0 

This kills the framerate completely.

When the electric charge runs out in some of the modules, converters turn off and the framerate gets (a bit) better.

Here is the quicksave, it needs KIS and KAS to load properly.
quicksave-mks-nullref.sfs.txt

The full log can be found here:
output_log.zip

KSP Version: 1.3.0.01804, language = en-us
USICore version: 0.4.1
MKS version: 0.52.1
USITools version: 0.9.2

This is reproducible with only MKS, KIS and KAS as mods.