But HTTP header is not for transferring arbitrary data. Some JSON writers(serializers) produce character sequences which are not valid as HTTP Header values.
So Please stop sending JSON Text directly as HTTP Header values.
Some encodings are required before transferring like binary to hexstring,
base64 encoding. Or we need to create own custom JSON serializers just for this.
Then We need new Dropbox-Api-Arg2 header for this.
Thx.