I might be a little late to the party, but I am encountering the same error that itkh and xiangyang pointed out. I am running on Windows 10. I extracted the PNG file listed in the error code. When I compared it to the file used by the base game, there is a noticeable difference to their respective dimensions.
Vanilla: construction-robot-shadow.png == 848x50px (2 rows of 16 shadows)
NRR: construction-robot-nuclear-shadow.png == 800x24px (1 row of 16 shadows)
Now, I skimmed quickly through the LUA code to see how the frames are extracted. I can see that there is a utility called 'util.multiplystripes' with a value of 2 and the file in question. This is not used the base game.
Instead of having these half-size files, would it not be faster and easier to take the image files from the base game and shift their tint from black to gray?
I have failed to load this mod on multiple occasions, but today, I decided to look deeper into the problem to try to understand why the failure is occurring.