Strings larger than about 800 docs throw a JSON.parse() error

I'm trying to pass a string to load() because iOS won't load from a URL. 
It happens on both Android and iOS. It attempts to parse a mystery line after the last line of the string at 4743 `line = JSON.parse(line);` but the mystery line appears to be a random part of the data, not split at a line break so it throws JSON Syntax Error. Is it a caching issue?
