Any way to know where exactly a save file goes wrong?

I did some minor savegame editing (I love the game and have played it through a couple times with some limited success, I was having a really successful game, and went bankrupt while having games released that would easily drag me out of debt in a couple weeks, while the autosave happened right when bankruptcy came, and my previous save was several hours prior), and I accidentally insetrted a lower-case “a” somewhere I shouldn’t. The error message when I try to load the autosave say “unexpected token a”, but doesn’t specify on what line. Is there any way to know, or am I condemned to either looking very carefully through my savefile or starting all over?