Failed to load mods: The given sprite rectangle (left_top=0x0, right_bottom=60x60) is outside the actual sprite size (left_top=0x0, right_bottom=60x40).
If this is being used as an icon you may need to define the icon_size property.
See the log file for more information.: base/graphics/icons/tooltips/tooltip-category-chemical.png
mods to be disabled:
ch-concentrated-solar (0.4.4)

any idea why that might be?

That's a new one :). Are you using any other mods here?

Oh nevermind yes this is my fault, it seems I used that sprite as a placeholder and it must have changed size.

Ok (apologies for message spam, I need to collect myself more before panicking and replying to these), I'm not getting this error on my copy, so first comment applies, any mods installed?

any mods installed?

yes hundreds ;-)