I was trying to work with a project that I had going yesterday with build 337 that worked fine, it would load my data. I upgraded to 341 and now I get JSON.stringify cannot serialize cyclic structures.
To test what I did then was go into the directory where the json file was being stored and I removed it. I figured I would get some kind of missing file or object type error. Instead I got the same error. JSON.stringify cannot serialize cyclic structures.
So I don't think it had anything to do with my data format, my data format is still working on my mac at home which is version 337.