The questions vary, but all tend to go down the same path. Something like…
I have 2 patches from October that when applied to my SCOM2012 test server stopped the System Center Data Access Service from running. The patches in question are MS12-054 and MS12-055. Has anyone had any problems with patches stopping this service?
This is a known issue that is outlined in Microsoft KB article 2730040.
The basics are that a specific update (update KB2677070) caused changes in the actual URLs associated with Windows Update. If the URLs have been hardcoded as exceptions in the firewall or proxy, neither the Data Access service or the Management Configuration service will be able to download new CTLs.
The full resolution is here: http://support.microsoft.com/kb/2730040