I Bought NI 15 Ultimate and added all of the serial numbers but some plug-ins is still not activated

Be sure to be using latest version of Native Access for your OS

But also do all the Mac users must do when using N.I. software :

ALL NI apps including NTKDaemon must have full disk access. : How to Enable Full Disk Access on macOS and disks must be of correct format : Notes on Network Drives and Disk Formats

Also then please check that iCloud Private Relay has been turned off : Native Access Error Message: "Download failed" (macOS)

Also then do not use Clean My Mac.

And quote Kymeia : if using Sequoia then N.I. apps must be added to the Local Network

Else try the My Products Are Showing As DEMO in Native Access , especially '2.Your activation fails because of corrupted or missing activation tokens' and '3. You have corrupted XML files'

Else what is the exact version of Mac OS ? , what is your N.A. version ? What is your Kontakt version ?

You are very welcome and thank you very much for providing feedback 🙂