mediaupload.exe stuck at "Progress: 0%"

[wizdum]

I am using an ATEM Studio HD, firmware version 7.5.2, video format is 525i59.94 NTSC 4:3 (though I had the same issue on firmware version 7.2) I have tried Windows 7 and Windows Server 2012r2 as the clients.

When I attempt to upload an image, the console outputs "Progress: 0%" until I kill it. I have allowed it to run for 5 minutes on a 14kb file, over a gigabit network, so I do not believe it is a bandwidth issue. Debug mode shows:
C:\Users\Administrator\Downloads\atemlib-2.0.2>MediaUpload.exe -n "Meeting2" -d
10.0.1.61 3 MeetingBlank.png
Switcher: ATEM Television Studio HD
Resolution: 720x480
Progress: 0%
Still upload lock obtained
Stills Callback: bmdSwitcherMediaPoolEventTypeLockIdle
Stills Callback: bmdSwitcherMediaPoolEventTypeLockBusy
Progress: 0%
Progress: 0%
Progress: 0%
Progress: 0%
Progress: 0%
Progress: 0%
Progress: 0%
Progress: 0%
Progress: 0%
Progress: 0%
Progress: 0%
Progress: 0%
Progress: 0%
Progress: 0%
Progress: 0%
Progress: 0%
Progress: 0%
Progress: 0%
Progress: 0%
Progress: 0%
^C
The same file uploads quickly via the ATEM Software Control program. Also, the MediaPool.exe file does correctly show all the information on the existing stills that have been uploaded, so it looks like the SwitcherLib is working and the program is able to connect to the ATEM Switcher.

Thank you.

UPDATE:
I was able to temporarily take the ATEM HD offline and switch to 1080p video format, and the uploader worked. So it looks like this is just a problem if SD video formats.