I have spent the afternoon implementing a client that will upload files to a shared Zoho Docs folder. I have gotten very close to success but have been unable to close the loop. My HTTP request seems to be going through just fine but I am getting the response  ERROR_WHILE_UPLOADING_DOCUMENT almost all the time. 

The file I am attempting to upload is a binary data file. I have been able to have success uploading a PNG file from disk, but the same code, pointing only at a different file (same file name, same mime type, etc.) fails with the above error message. It also fails if I try to upload a text file.

The api docs do not specify a restriction on the files I can upload, however, I have tested uploading these files by hand and I have also been unable to upload them. Attached are the files I have been trying to use.

What is going on and how can it be fixed?