I have two work laptops (Windows and MacOS), one is mostly used for writing music, the other for live performances, as there are plug-ins for work that are available only on one of the platforms), and every time an update of the operating systems comes (I'm in the program for testing the final builds), the registration goes down. Each time you need to enter the registration data in the plugin (serial number, etc.). This creates inconvenience when working with the plugin (Synthplant). Is this a global problem or a local problem due to test builds of operating systems, as in my case?

It sounds like a local problem due to your machine changing machine-id on every OS update. We know this can happen with major updates. The easiest solution for you is to run the Sonic Charge Authenticator when this happens, and it will take care of the authorization for you without the manual key registration.

To download the latest Synplant 1 version, look for the multi-installer from 2022-11-25 under our download archive. During installation you can pick to only install Synplant.