I encountered this issue today on a FreeBSD 9.1-RELEASE-p4 system.
[dvl@sdev01 ~]$ sudo freebsd-update -r 9.3-RELEASE upgrade Password: Looking up update.FreeBSD.org mirrors... 5 mirrors found. Fetching metadata signature for 9.1-RELEASE from update5.freebsd.org... done. Fetching metadata index... done. Fetching 1 metadata files... done. Inspecting system... donet The following components of FreeBSD seem to be installed: kernel/generic src/src world/base world/lib32 The following components of FreeBSD do not seem to be installed: world/doc world/games Does this look reasonable (y/n)? y Fetching metadata signature for 9.3-RELEASE from update5.freebsd.org... done. Fetching metadata index... done. Fetching 1 metadata patches. done. Applying metadata patches... done. Fetching 1 metadata files... done. The update metadata is correctly signed, but failed an integrity check. Cowardly refusing to proceed any further. [dvl@sdev01 ~]$
The solution: freebsd-update fetch install and then a reboot.
$ sudo freebsd-update -r 9.3-RELEASE upgrade Looking up update.FreeBSD.org mirrors... 5 mirrors found. Fetching metadata signature for 9.1-RELEASE from update4.freebsd.org... done. Fetching metadata index... done. Inspecting system... done. The following components of FreeBSD seem to be installed: kernel/generic src/src world/base world/lib32 The following components of FreeBSD do not seem to be installed: world/doc world/games Does this look reasonable (y/n)? y Fetching metadata signature for 9.3-RELEASE from update4.freebsd.org... done. Fetching metadata index... done. Inspecting system... done. Fetching files from 9.1-RELEASE for merging... done. Preparing to download files... done. Fetching 39469 patches.....10....20....30....40....50....60....70....80....90....100....110....120....130....140....150....160....170....180....190....200....210....220....230....240....250....260....270....280..
