WordPress Upgrade Preflight Check

WordPress logoUpgrade Preflight Check is a plugin that will attempt to check your other plugins and themes for problems that may cause errors when upgrading to WordPress 2.3. Run this before upgrading and it may save some headaches. It works in version 2.3 too and may be useful to help identify the cause of errors.

About WordPress 2.5 and Beyond

The current version of Upgrade Preflight Check only checks for problems in upgrading to WordPress 2.3. This is still useful if you’re upgrading from a version prior to 2.3 but obsolete otherwise. I will not be updating this plugin further.

Important Note

Having or not having problems listed in the Upgrade Preflight Check report is not a guarantee of compatibility or failure. It is designed as a starting point to help you follow-up on potential problems. Please check individual plugin and theme Web pages to fully verify compatibility. (And always make a backup before upgrading.)

How It Works

This plugin works by scanning for the appearance of text within plugins and themes that may indicate compatibility problems.

It currently looks for the following:

  • Use of the old category tables that are now gone.
  • Use of wp-admin/upgrade-functions.php, which has been moved and renamed.
  • Use of the get_the_title function, which works a little differently.
  • Use of deprecated permalink functions, which still work for now but should be replaced.

Each of these conditions comes from discussions on the wp-testers mailing list and various blog posts during the time leading up to the WordPress 2.3 release. More details are shown at the bottom of the report.

Installation and Use

  • Upload upgrade-preflight.php to the /wp-content/plugins/ directory.
  • Activate the plugin through the Plugins menu in WordPress.
  • Use the Upgrade Preflight menu under Options in the WordPress admin panel to generate a report.
  • There is no need to leave the plugin activated when not using it. Disable it when done.


Download from smithsrus.com: Upgrade Preflight Check

Samuel Aguilera was nice enough to create a Spanish translation that you can download from his site.

Version History

Version 1.1, 10/22/07

  • Additional checks for plugins knowing about the new tag system so they don’t get flagged as incompatible. i.e., Sitemap Generator 3.0.
  • Internationalization of text. If you do a translation please send the files over. I’ll post them here for download and give you credit.
  • Miscellaneous clean up.
  • Added GPL license text.

Version 1.0, 9/26/07

  • Initial release.


I’ve been asked for a way to make donations. If the plugin saved you time or trouble and you want to say “thank you” in that way, you may do so through a PayPal donation or the Amazon Honor System.

95 thoughts on “WordPress Upgrade Preflight Check”

  1. Brilliant. I wish I’d know this existed yesterday morning before upgrading. would have saved me hours of headaches.
    Please do this for all future releases.
    Many thanks

  2. Nice – pointed out some potential issues that might have had me scratching my head otherwise. Now I know which plugins to thump 🙂

  3. Great idea. 🙂 I disabled all the plugins that could be causing problems, but it looks like it may be the theme. Well, now to see about fixing that… Thanks!

  4. Pingback: General To Do’s
  5. Thanks for this one. It solved a problem with several plug-ins after I had already upgraded to 2.3. A small donation will follow for you efforts. Thanks again.

  6. This is by far one of the most useful WP plugins I’ve come across in using WordPress. Thank you very much!

    I do hope that you’ll consider carrying-on the torch to release Pre-flight Checks for future upgrades as well. Or, perhaps see if Matt and the team would consider an official plug-in, making this an in-house ‘thing’ prior to major upgrades from now on.

  7. Thank you so much! I run a huge website which relies on a bunch of plugins in order to work properly and your wonderful plugin just saved me a lot of work.

  8. Hi, just noticed that the plugin doesn’t redo the check. I had a bogus upgrade-functions.php in my code, removed it, but it still complains about it.

  9. Fab plugin – thank you. Now I just need to add the dodgy plugins back in, one by one, to see which was the culprit …

  10. That was actually very usefull. But I’m still dreaming for the day that wordpress will be able to update itself. =)

  11. helpful, thx. when preping for wp.2.3.2 i noticed that the path to upgrade.php is not wp-admin/include/upgrade.php but wp-admin/includes/upgrade.php — notice that little “s” … 😉

  12. Thanks Peter. I’ll get that fixed in the next round. I was just about to investigate why it was giving false positives on a few plugins. That was the answer. 🙂

  13. ok, now here is a really good idea! how many times are there incompatibilities when upgrading. Thanks for a great idea for a plugin. i echo the user above about wordpress updating itself – would love to see that!

  14. I have been a frequent visitor of this blog for some time now, so I thought it would be a good idea to leave you with my thanks.

    Jim Mirkalami

  15. Wow, thanks for this post. I have had so many problems upgrading and with certain themes. Thanks again

  16. Thanks for this, it saved me hours of hassles. Another cool plugin worth mentioning on the topic of Upgrading WordPress, is the Instant Upgrade which makes the actual upgrading a snap (it doesn’t check for problems though) so we still need to run your PreFlight Check first.

  17. The upgrade preflight check is very usefull, it saves a lot of time and trouble at the last update for one of my clients

  18. Any news on a 2.5 checking version?
    Also, hope you don’t mind the suggestion, but a ‘subscribe to comments’ type plugin might be useful on this site…

  19. @Chris: Yes, I’m working on a version to help with the WordPress 2.5 upgrade. I’ve been keeping an eye on the development and noting things that may break. I’m also hoping someone will do a post about things to watch for in upgrading to WordPress 2.5. There were a few of those posts for 2.3 that were helpful in making my list of things to check. Suggestions from all are welcome.

    Good idea on the comments subscription. I’ve been meaning to do that but just haven’t gotten around to it. Do you have a favorite plugin that is working well for that purpose?

  20. Glad to see that you’re still working on this plugin. I’ll be looking forward to it as and when 2.5 comes out. Cheers.

  21. @Chris, Currently the plugin does not check anything specific for WordPress 2.5. It’s still useful if you are coming from a version less than 2.3, though. I’m still debating wether to upgrade for 2.5 specific issues because there really aren’t that many of them.

  22. would love to see this for 2.5, having a bunch of sites with tons of plugin’s, I don’t look forward to manually checking them all. If you do upgrade this, it would be appreciated. THanks!!

  23. This is a great plugin, and I really think you should develop an upgrade for the 2.5 version. Is there a way to make this plugin static among upgrading wordpress versions? Since WordPress ALWAYS have updates.

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