I had exactly the same error response when trying to download a file using DownloadFile
. Browsing the folder hierarchy or uploading files was working fine. After I found this issue on the sharpbox bug tracker I changed my .NET C# console application from framework version 4.5 to 4.0 and all of a sudden it worked.
So this tells me that sharpbox v1.2.0.542 (via NuGet) is not very stable and you might want to use another C# wrapper or write one yourself using the DropBox API directly.