The long delayed version 1.5.1 of WordPress MU has just been released. If you don’t want to read the rest of this post head to the download page and grab the zip file or tarball but make sure you come back here to read the upgrade docs.
This release of the popular multi-blog version of WordPress is synced with WordPress 2.5.1 and so has all the great features as well as bug and security fixes that went into that release.
Upgrading from a previous release
As long as you haven’t modified any core files, you can copy the files in 1.5.1 over your current install. Database upgrades will happen transparently in the background. The new salted hashing on passwords requires two constants, SECRET_KEY and SECRET_SALT to be defined in wp-config.php. If you upgrade and you don’t change wp-config.php your users will appear logged out when they go to a different blog. That’s why MU will display an ugly warning message to site admins with the two lines when they log in to the backend.

If you run into trouble, remember to check the forum and Trac. Someone else may have already answered your question.
25 replies on “WordPress MU 1.5.1”
[…] “WordPress MU 1.5.1″ beim WPMU-Entwickler Donncha […]
[…] Edit2: Mer info om WPMU 1.5.1 […]
[…] MU 1.5.1 Released Doncha has done a great job getting WordPress 2.5 ported over to MU. MU 1.5.1 is available […]
Thank you for all your hard work on this Donncha! Much appreciated.
[…] har Donncha tagget den nye versjonen til WordPressµ (Multi User) til 1.5.1. Det vil si at den er nå […]
After a fresh install I am redirected to /wp-admin/install.php, which is missing… What can I do?
Thank you
[…] MU 1.5.1, final version, is ready to download. Donncha just posted in his blog how to upgrade: Upgrading from a previous release As long as you haven’t modified any core files, you can copy […]
[…] Mu 1.5.1 is out. Donncha announced: The long delayed version 1.5.1 of WordPress MU has just been released. If you don’t want to read […]
[…] WordPress MU 1.5.1 […]
[…] The biggest release of WPMU since 1.0 is upon us, let there be merriment and many painless upgrades. […]
[…] Release announcement […]
[…] Updated: Donncha O’Caoimh has announced the update of WordPressMU, the multi-user version of WordPress. It is now WordPressMU 1.5.1 and synchronizes with WordPress […]
Thank you for great mu-1.5.1. I have to wait for it for a very long time 😉
[…] http://ocaoimh.ie/2008/05/12/wordpress-mu-151/ […]
WordPress MU 1.5.1 リリース…
WordPress MU › Download »
WordPress MUã®æœ€æ–°ãƒãƒ¼ã‚¸ãƒ§ãƒ³ã¨ãªã‚‹ã€WordPress MU 1.5.1ãŒãƒªãƒªãƒ¼ã‚¹ã•れãŸã€‚今回ã®ãƒãƒ¼ã‚¸ãƒ§ãƒ³ã¯WordPress 2.5.1ã«ã‚ã‚ã›ãŸãƒãƒ¼ã‚¸ãƒ§ãƒ³ã‚¢ãƒƒãƒ—ã®ã‚ˆã†ã§WordPress 2.5.1ã®æ©Ÿèƒ½ã¯…
[…] News: WordPressMU 1.5.1 is out: I think everyone who runs MU-powered sites has been waiting for this since WP 2.5 came out. So […]
Thanks tons, donncha! 🙂
[…] Updated: Donncha O’Caoimh has announced the update of WordPressMU, the multi-user version of WordPress. It is now WordPressMU 1.5.1 and synchronizes with WordPress […]
[…] Updated: Donncha O’Caoimh has announced the update of WordPressMU, the multi-user version of WordPress. It is now WordPressMU 1.5.1 and synchronizes with WordPress […]
[…] Updated: Donncha O’Caoimh has announced the update of WordPressMU, the multi-user version of WordPress. It is now WordPressMU 1.5.1 and synchronizes with WordPress […]
[…] Updated: Donncha O’Caoimh has announced the update of WordPressMU, the multi-user version of WordPress. It is now WordPressMU 1.5.1 and synchronizes with WordPress […]
[…] blogs.voxeo.com to WordPress MU 1.5.1, the latest version. I’ve been wanting to do this since the release a month ago but I’ve held off to monitor the WPMU Forums to see what upgrade issues there were. The other […]
[…] http://ocaoimh.ie/2008/05/12/wordpress-mu-151/ […]
Thanks for your great contribution to the wpmu community. I want to upgrade my 1.3.3 to 1.5.1 but i cannot find the install file and recommendation / issues with upgrade — could you point me in the right direction?
I have exactly the same problem than Murphy :/