Hey Optera, I hope you see this here with the lack of notifications.

Failed to load mods: The given sprite rectangle (left_top=0x0, right_bottom=64x64) is outside the actual sprite size (left_top=0x0, right_bottom=32x32).
Sprite name: ShinyBobGFX/graphics/icons/fusion-reactor-equipment-1.png.
If this is being used as an icon you may need to define the icon_size property.: ShinyBobGFX/graphics/icons/fusion-reactor-equipment-1.png

If you define your icon sizes (I didn't look at the code), I guess I should report this over at the Shiny set of mods, too?

Looks like shiny tries to change a single layer icon into a multi layer and struggles with my uncommon 64x64 icon size.

Let them know and I'll also change my icon size to the commonly used 32x32 until Factorio supports layered icons of different sizes.

Multi-layered multi-size icons should be properly supported since 0.16.31 according to the changelog: "Fixed drawing icons with layers when layers didn't have same source size as main icon."

It kinda is at the point where it doesn't outright crash if each layercontains icon_size.
However layering different sizes will still crop wrong sizes from the atlas instead of scaling icons.