We've had quite some feedback from our recent 4.0.0 release. As is to be expected in a release that has many changes, some issues sneaked in. To address most of them, we released Openfire 4.0.1 today.
This release contains various changes, but most importantly fixes problems introduced in 4.0.0 related to LDAP and certificate store management. The complete changelog is available here: Openfire Changelog
You can download the new release from the download section on the IgniteRealtime.org website: Ignite Realtime: Downloads
The SHA-1 checksums for the various downloads:
Mac OS X
Redhat / CentOS
Debian / Ubuntu