V9 is rock-solid on older operating systems like Windows 7/8 and macOS Mavericks through Mojave.
Older operating systems like macOS High Sierra, Mojave, or Windows 7/8 cannot run modern Waves V14 or V15 plugins. V9 is the perfect match for legacy machines.
Do not try to run V9 and V14 plugins simultaneously in the same DAW session, as this often causes crashes. To help you get this running perfectly, let me know: Operating System (and version) are you using? (Ableton, FL Studio, Logic, etc.) are you targeting? Are you trying to recover purchased licenses or setting up a new machine
I can provide the exact compatibility requirements and installation steps for your specific system setup. Share public link