Iced Coffee

Image basically explains it all, I click save as and it calculates the file size to be (error) so i click save and it loads for a minute or 2 then pops up with this error. I tried saving as almost every file format except .pdn, same error every time. why? I was bored and had a few bucks left in an old VPS account, so why not rent out a 24 core 96gb ram server for a few hours and render a nice high res julia fractal