Well, sort of. I think I found the issue that was causing the file corruption (after painstakingly redoing the entire thing umpteen times all night long, until I found the culprit). It seems some of the text I copied and pasted from the website for the character class details had web links in them, (either that, or the text was just simply too long, since it still corrupted the file even when I copied/pasted it as plain text to and from a notepad document). Once I got rid of that part, it seems to be saving normally again.

Now that it's 5 a.m., I finally got done what should have been so simple, and would have been done many hours ago. One character sheet. Pfft. Technically, I'm still not done with it, because I have to fill out the backstory, and all that jazz.