Upgrading FreeBSD should only be attempted after backing up _all_ data and configuration files.
====
+[[upgrade-rc]]
+== Upgrading from Existing Base System Package Installs
+[IMPORTANT]
+====
+For users of PRERELEASE, ALPHA, and BETA builds of FreeBSD 15.0, due to late-breaking changes in FreeBSD.org infrastructure, it is not possible to upgrade directly using the man:pkg-upgrade[8] utility.
+====
+
+Users should either force-install the package:FreeBSD-pkg-bootstrap[] package from the official release base system packages, or alternatively manually copy the required files from a source tree checkout of `15.0-RELEASE` tag, or a later commit in `STABLE` or `CURRENT` branches.
+
+The recommended, and most secure approach, is using the source tree checkout of any of head, stable/15, or releng/15.0 branches after 2025-11-27 22:00 UTC.
+Users who do not have up to date sources installed may use a less secure, but simpler approach, validating the checksums after installation. As these are architecture-independent files, the checksums will match on all platforms.