I'm having the same issue while trying to update a mod that has already been published. After selecting the archive file ("Select a zipped mod to upload"), the selector box says "Status: Ready File: file.zip (xx KB)", but when I press "Submit" all I get is this same net...

Just a quick and dirty hack: https://mods.factorio.com/mods/Valck/Honck Feel free to fold any changes into your mod. This adds car and tank horns (don't expect a battleship fog horn on the tank, it's the same as the car horn, as I'm told tanks have rather wimpy sounding horns if they have any at all...