This is fixed in the latest release
As items like construction robot, ammos, and fuels dont have sprites that are usable in sprite buttons, this mod had a bit of code that creates them from the items icon. As it assumed all item icons are 64x64, it caused a crash when it attempted to create sprites out of icons that were not 64x64.
Thanks for pointing this out and I apologise if you spent time working it out, the function dynamically checks for the icons size and scales the sprite correctly