I have been running a TikiWiki site for a while now without any problems and last night wanted to set up a new one on the same machine. I already had the files downloaded from the original install, so I was all set.
I followed all the usual steps; set up the database with a new user with all permissions, set up the file permissions on the Tiki directories with setup.sh, ran the tiki-install.php. However, I noticed that when I logged in and tried to go to adminstration pages it would take a very long time to respond and then place an error at the top of the page after a minute or two. The error I got was: Notice: Undefined variable: major in /path/to/tiki/lib/twversion.class.php on line 114.
I was confused by this because I was sure I had done all the install steps correctly. I decided to look at the file giving the error and realized that it was having a problem trying to update. Sure enough I noted that tikiwiki.org was down. The solution was to turn off the release check under general preferences and settings. As I suspected, Tiki no longer complained when viewing certain admin pages.
I bring this to everybodies attention because, although this is only a minor annoyance (with a relatively small probability of happening), for the complete novice user it might be enough to put them off using Tiki, dismissing it as a product that doesn't work. My other Tiki doesn't have a problem so, without knowing exactly how the code works it looks like as long as Tiki is able to check at least once after install, it will have some values stored that will be enough to prevent Tiki complaining about uninitialized values. To this end, the code should be modified to recognize potential/possible failure of initial release check, so that the user can be informed that the release check feature is temporarily unavailable. I also thought about having an alternative site (distinct from tikiwiki.org) be available for the sole purpose of checking for new versions, but then unless you have updates available for download from that alternate site too then this is pointless, unless developers don't mind having yet another thing to maintain.
I haven't submitted this as a bug because it's not a bug per se, but I thought people should be aware (assuming they aren't already).
[Edit] I just realized that my post is related to this post: How disable twversion.class.php fuctions