Unable to Upload File Through iControl REST Interface

I am attempting to upload a file through the iControl REST interface using iControl BIG-IP v12 getting a response code 400 with a response body of:

{"remainingByteCount":0,"usedChunks":{"0":5},"totalByteCount":5,"localFilePath":"/var/config/rest/downloads/test.txt","temporaryFilePath":"/var/config/rest/downloads/tmp/test.txt","generation":0,"lastUpdateMicros":1475011484946186}

 

I am using token auth. I am at a loss as to why this is giving back a 200, any help would be greatly appreciated. I can answer any questions that will help give us clues.

Here are the headers that I have:

 

Content-Type: "text/plain"
Content-Range: "0-4/5"
Content-Length: "5"
Transfer-Encoding: "chunked"

 

And the response debug data:

 

server: "com.f5.rest.common.RestRequestSender"
x-frame-options: "SAMEORIGIN"
pragma: "no-cache"
cache-control: "no-store, no-cache, must-revalidate"
expires: "-1"
content-length: "231"
content-type: "text/plain; charset=ISO-8859-1"
content-range: "0-4/5"
local-ip-from-httpd: "xxx.xxx.xxx.xxx"
accept-encoding: "gzip;q=1.0,deflate;q=0.6,identity;q=0.3"
x-forwarded-server: "localhost.localdomain"
x-forwarded-proto: "http"
x-forwarded-host: "xxx.xxx.com"
x-content-type-options: "nosniff"
x-xss-protection: "1; mode=block"
content-security-policy: "default-src 'self'  'unsafe-inline' 'unsafe-eval'"
strict-transport-security: "max-age=16070400; includeSubDomains"
connection: "close"