One of the reasons you possibly could be dealing with an upload error message is because we found a bug in version Mac OS X 10.12.
If you extract the dmg (or double click it) and run the app in the same folder and run it, auto-updates will not work.
The reason is in 10.12 the directory path during download is randomized to a private location. This is for security purposes. To fix this, double-click dmg file operation now (From version 5.8) installs explicitly in Applications folder.
More info here: