Sorry, there is no economic sense in closing this corporation. (White Giant)

What might cause this message in the title? My corporation "Romara Elementary schools" has been hemorrhaging money for a while, so I lowered the hiring levels and started a new corp to take on the people, but I got this message when trying to close it. It isnt a new corporation so I dont know what would cause this.

if the corp is over 100B you can't close is, no matter how bad or unwanted it is for some reason. It's pretty annoying but just reduce hiring and production to 10% and wait for the value to tumble

i assumed it was a result of the auto setting 'economic protection'. Can't back that up tho

Thats right as far as I understand it Pencil.