PSP 2018: Error 1920

[Fredalf99]

I'm trying to install my newly purchased uppgrade of PaintShop Pro X9 to PaintShop Pro 2018 Ultimate.
I'm encountering the following error message:
"Error 1920. Service Corel License Validation Service V2, powered by arvato (PSI_SVC_2) failed to start. Verify that you have sufficent privileges to start system services."

I'm on Windows 10 (64-bit). I've tried to start this service manualy but it won't start. I've tried with disabeling Comodo Internet Security but still no luck. Any ideas on what to try next?

[Zantara]

Try running it as an administrator, with Windows Defender disabled as well. You need any anti-virus, malware-scanner, firewall or any other form of protection (temporarily) disabled.
Disabling your Internet security isn't enough. Windows 10 as a standard "protects" you with Windows Defender. Rightclick in your taskbar on the Defender icon and disable all the services.

I tried to install 2018 and the file wouldn't even open. Until I remembered that you had to disable all protection with previous versions and run the setup als an administrator.

[Fredalf99]

Thanks! Problem solved.
After stopping every process and service related to security I finaly managed to complete the installation. Rebooted the computer after completion of installation and tried to install the latest update to Aftershot and encountered the same problem. But at least this time i knew exactly what to do.
It’s odd though. I previously installed both X8 and X9 under Windows 10 on this computer without having this issue.