I'm trying to sort out updating server software to fix some found security issues, but before I do, I need to make sure that this won't affect the website that's currently running. I know for example updating PHP can cause issues with deprecated function use. I'm doing this on a server that I have had no previous involvement with, so I cannot account for code quality and am doing a separate review for PHP.
Does updating Apache have a similar potential problems? we'll be updating from Apache 2.2.11?