According to its official website, version 6 of SoundTrek Jammer Professional exists and even though it only mentions Windows XP, Vista, 7 and 8 as supported operating systems, I installed it on Windows 10 and it worked without any kind of issues.
If you can't or don't want to update from SoundTrek Jammer Professional 4, you could try running the application in compatibility mode with an older version of Windows: right-click the executable, press Properties, then go to the Compatibility tab. Once there, check the box marked Run this program in compatibility mode for, then select Windows XP or an older version and press Apply.
Alternatively, you can set up a virtual machine, install an older Windows version on it, then run the program through that virtual machine.