AngusMcG: The problem seems to be that it tries to upload the
Player-prev.log file in the save game folder. I've only played a few games and it's already over 1.7 GB in size.
I have the same problem and agree that it's the player.log and player-prev.log files. Mine are almost 1GB too (split 390 and 480MB respectively),orders of magnitude larger than the next nearest game I have using the same file structure (Per Aspera gets to about 15MB)
You can simply delete the player-prev.log file for a quick fix, but the problem is after every exit the player.log will be renamed to replace it and they continue to compound each session. It looks like the log file grows about 20-50MB per exit at least.