The game was expecting the icon to be 64x64 pixels (the default icon size), but the icon for your mod is 32x32. Editing the icon to be twice as big fixed the crash.

I had same error and couldn't fix so i had to delete

make the icon from 32x32 to 64x64 and it should work. same icon name.

yes it fixes. just open icon with paint and resize it to 64x64 and save

where would you find the icon? Game is steam version, and mod is installed via In-game Mod portal.
EDIT: nevermind. found it. For the sake of documentation:
Search %appdata% and open the roaming folder
locate factorio >> Mods >> And unzip Miner Planner.
Graphics >> Icons >> Open, edit, save.
Re-zip the mod. close folder and launch.