Planning to install CA Access Gateway (SPS), is it possible to install Secure Access Gateway (SPS) 12.8 on Windows 2019 server?
At first glance, Yes, it's possible starting version 12.8SP5 and a more recent version to get support and have a certified environment (1).
(1)
Symantec SiteMinder (previously CA Single Sign-On) 12.8
| SiteMinder | Windows Server |
| Component | |
|----------------+----------------|
| Access Gateway | 2019(9) |
| 64 bit | |
9. Windows 2019 (Standard, Essential & Datacenter Editions) and Red
Hat 8 are supported with 12.8.05 and later releases.