WordPress Theme Editor

I usually use the wordpress theme editor to update my themes files and such. Today, I update the file, and it says it’s been updated successfully, but the text field is blank. None of my code is there. I visit my site, and (i was editing footer.php) my footer isn’t there anymore. I press the back button on the theme editor, copy the code, open notepad, and do it manually. It worked, but then I edited it again using theme editor, same thing happened, and this time it didnt allow me to upload my file. I got an error saying that I had no space left on my device. When I’m positive I have space on my site. WordPress only takes up about 6 MB, and I have I think 100 MB. This might be a web host issue. But maybe a wordpress issue. Any ideas?