As I mentioned in the footer of the post on the Hudson 1.344 release, there were a couple big regressions in the 1.344 release that were causing a number of users issues (such as issue 5536 and issue 5546).
As a result, Kohsuke and the team have quickly pushed out a hot-fix release: 1.345. Here’s the break down:
If you have already updated to 1.344, your "Update Center" is most likely busted and you’ll need to download the
hudson.war file manually.
You can go grab the latest .war file straight from
hudson-ci.org or if you’re using a native package, use your package manager to upgrade.