15 was a long time ago (9 years) and was not designed to be run on Windows 10.
Having said that, it will run as I have it on my system still.
Make sure you have the correct version of Java installed and also I thing it requires Quicktime to be installed.
Both can be found on the original installation disk for 15.
Do you have an actual license for 15?
Or are you trying to use a downloaded and cracked (un-licensed) version of the software - if so this could also be the problem.
Barry.
One of the forum moderators.
Versions 6.5 to 27
i7-10700 @ 2.9Ghz, 32GB ram, GeForce RTX 2060 (6GB), Windows 10
Lenovo Thinkpad - i7-1270P 2.20 GHz, 32GB RAM, Nvidia T550, Windows 11