com.cloudrail.si.exceptions.HttpException: Error in call to API function "files/download": HTTP header "Dropbox-API-Arg": could not decode input as JSON

[gandulf]

com.cloudrail.si.exceptions.HttpException: Error in call to API function "files/download": HTTP header "Dropbox-API-Arg": could not decode input as JSON
	at com.cloudrail.si.services.Dropbox.download(Dropbox.java:722)
	at com.dsatab.cloud.HeroExchange.download(HeroExchange.java:447)
	at com.dsatab.cloud.HeroExchange.synchronize(HeroExchange.java:425)
	at com.dsatab.cloud.HeroExchange.getHeroesByType(HeroExchange.java:621)
	at com.dsatab.cloud.HeroExchange.getHeroes(HeroExchange.java:526)
	at com.dsatab.cloud.HeroesSyncTask.loadInBackground(HeroesSyncTask.java:65)
	at com.dsatab.cloud.HeroesSyncTask.loadInBackground(HeroesSyncTask.java:15)
	at android.content.AsyncTaskLoader.onLoadInBackground(AsyncTaskLoader.java:312)
	at android.content.AsyncTaskLoader$LoadTask.doInBackground(AsyncTaskLoader.java:69)
	at android.content.AsyncTaskLoader$LoadTask.doInBackground(AsyncTaskLoader.java:57)
	at android.os.AsyncTask$2.call(AsyncTask.java:288)
	at java.util.concurrent.FutureTask.run(FutureTask.java:237)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
	at java.lang.Thread.run(Thread.java:841)