Throws 500 error accessing a nonexistent file

[AshKyd]

We're getting error 500 trying to access files that don't exist. I'm not sure what's getting us into this condition, but I think it's happening on this line.

I propose we don't pass the error back, because if it can't read the file I think this should hit the next item in the waterfall and re-download the file rather than straight up erroring.