The CSS fork distributed with DC RUM is supported on Windows only since 12.4.0. The information you're looking for is here: Release to release Changes and Differences
Central Security Server distributed with DC RUM is only supported for installation on Windows and with Microsoft SQL Database. Linux and Unix based systems and Oracle databases are not supported. To use CSS on these platforms, you need to install the CSS distributed with BSM.
@Tarjei U., I talked to the BSM development and the statement in the doc is unfortunately farfetched. That was the original plan, but never materialized. The BSM 12.4 is released soon, however, the BSM bundled CSS will stay at 12.3.x not to cofuse it with the DC RUM bundled CSS. It will work with BSM 12.4 but will be blocked by RUM Console 12.4.x. In fact, DC RUM 12.4.x was never tested with Linux CSS. The only supported
option for customers with DC RUM 12.4.x and BSM 12.3.x and higher is to have
two separate CSSes. We also do not provide means to sync or migrate data between MSSQL and Oracle databases.
I'm changing info in the docs.