FileTransfer Download null errors

FileTransfer download is erroring on it's 'win' function. The result being passed in is null on line 170. The 'win' function is called multiple times with incremental progress, but on the final call, it is passed null instead of proper result.

So the file is there and fine, but my callback is not triggered because the 'win' function is erroring.

[Error] TypeError: 'null' is not an object (evaluating 'result.lengthComputable')
win (FileTransfer.js, line 172)
callbackFromNative (cordova.js, line 292)
(anonymous function) (cordova.js, line 1046)
nativeEvalAndFetch (cordova.js, line 1054)
nativeCallback (cordova.js, line 1043)