Hello, i have run into the exact same problem, while the trial worked just fine, the paid version doesn't start.
The firewall and anti-virus have been triggered on and off without any changes.
There is no Spine Log and oppening up the "Spine.Com" on cmd gave me this answer:
"C:\Program Files (x86)\Spine>Spine.com
Picked up _JAVA_OPTIONS: -Xmx6G
Invalid maximum heap size: -Xmx6G
The specified size exceeds the maximum representable size.
Failed to create Java VM: -6"
I have tried other methods but none seems to make it function whatsoever, i have yet to reach a solution.