Apple released MacOS 10.15.4 on March 24, 2020 as an enhancement to MacOS Catalina.
Trend Micro has tested the Apex One (Mac) agent together with MacOS 10.15.4 and noticed that the following pop-up may appear after upgrading:
Legacy System Extension
Existing software on your system has loaded a system externsion signed by "Trend Micro, Inc." which will be incompatible with a future version of macOS. Contact the developer for support.
The pop-up should only appear once after the upgrade. All agent functionality has seen to be working with MacOS 10.15.4
For any further concerns, contact Trend Micro Technical Support.