PD9 was released in 2010, back when Win 7 was brand new and many people were still on WinXP or Vista. The last patch for that program came out 11 years ago, and in all honesty the program is woefully out of date as it doesn't support any new nVidia GPUs and is lacking many modern features.
If you've installed it on a new Win10 or 11 system you can try reaching out to CL tech support to see if they can help you resolve the issue. However if you've installed it on a system with an older OS, they will likely not be willing to help as described
here.
Overall I think you'll have a much better editing experience if you got the latest version (PD21/lifetime license or PD365/subscription).