About the Legacy System Extension notification
As of macOS 10.15.4, macOS is displaying the following Legacy System Extension notification to our security product users:
With this notification, Apple is informing Mac users that macOS Catalina will be the last macOS version to fully support "kernel extensions" or so-called "legacy system extensions". Note that this requires no action from you. F-Secure is working on updating our products so that they will continue working with the next macOS version expected to be released later this year. We expect our products to have been updated to support the next macOS version by the time it will be released.
This applies to all our security products running on macOS; that is F-Secure SAFE, F-Secure Anti-Virus, F-Secure TOTAL, Computer Protection for Mac, and Client Security for Mac.
For more information on the discontinuation of support for the legacy system extensions and the reasons for phasing out them, see Apple's support article About legacy system extensions.