A Bug in Chrome 45 Causes WordPress Admin Menu to Break

Within the last five weeks, several people have reported an issue in Chrome that breaks the WordPress admin menu. If you hover the mouse cursor over menu items in the sidebar, they’ll occasionally fall out-of-place.

Chrome WordPress Admin Menu Using Chrome 45.0.2454.85, I’m able to inconsistently reproduce the behaviour reported in the ticket. Through the process of elimination, users discovered Chrome is the software at fault and not WordPress.

The source of the problem stems from Slimming Paint which is enabled by default in Chrome 45. Disabling slimming paint fixes the issue.

To disable this feature, visit chrome://flags/#disable-slimming-paint in Chrome and Enable the Disable slimming paint option, and make sure the other two Enable options are disabled because they will override the Disable option.

If this sounds confusing, please refer to the following screenshot provided by Samuel Wood.

Disable Slimming Paint Options
Disable Slimming Paint Options

Chrome’s development team is aware of the issue and is working towards a solution that is marked for release in Chrome 47. Until then, users are encouraged to disable Slimming Paint until Chrome fixes the issue.


95 responses to “A Bug in Chrome 45 Causes WordPress Admin Menu to Break”

  1. I thought my site was compromised somehow (corrupt files,etc…). One easy fix for me was to collapse the menu to icons, and then expand it again. Very annoying… .

    At least the Customizer is fine though !!!

  2. To disable this feature, visit chrome://flags/#disable-slimming-paint in Chrome and click the disable link.

    Note that this is slightly confusing here, because it’s bloody Chrome so of course it is.

    You actually have to “Enable” the “Disable slimming paint” option, and make sure that the other two “Enable” options are actually disabled, because they will override the Disable option.

    If you got a headache from reading that, you’re not alone.

    Just go by this picture of what it should look like instead:
    Cloudup qhfjldalkv4

    That’s how it needs to be. This will disable the problematic code in Chrome and allow the menus to render normally.

    • You actually have to “Enable” the “Disable slimming paint” option, and make sure that the other two “Enable” options are actually disabled, because they will override the Disable option.

      Yeah, that made me laugh pretty hard!

  3. yet another win for automatic updates. I wish I could say that my browser is different (firefox), but it isn’t :(. Maybe time to seriously consider using IE.

  4. Thank you! I’ve been trying to figure out how to do this for a month now. I ended up rediscovering Firefox… Perfect fix. Seriously. Thank you.

  5. oh darn god. I was happy I’m not in the issues group, until I discovered my Chrome is stuch on version 44… now it will go to 45 when I restart it :(

  6. I’m using 45.0.2454.85 m (64-bit). I don’t see a second phase to disable and setting the first two flags as instructed doesn’t fix the issue.

    • Try the plugin I mentioned above, it worked for me.
      It’s a CSS fix and you can delete it once Google Chrome fixes the bug.

      • I don’t have three entries as described/shown either (Linux 64bit), but did find that if I start Chrome using the –disable-slimming-paint flag the issue goes away.

  7. Now if they could just fix the constant memory sucking and crashes that also came with 45.0.2454.85. I upgraded to this version today and Chrome uses up about 1,000,000k every 2 hours which crashes the whole browser. Have to now use Firefox only again.

  8. THANK YOU THANK YOU THANK YOU! I almost resorted to using IE because this bug was driving me insane. You are my new favorite person today.

  9. Looks like they moved fast; mine (on the beta channel) just updated to “46.0.2490.13 beta-m” and everything’s working again in the admin sidebar.

    • No, they have not made any fixes yet. Chrome 46.0.2490.13 beta-m (64-bit) definitely still has the problem, at least it does on Windows 10.

      The problem is slightly random in nature. You don’t see it every time. You do see it quite a lot of the time though, it’s very reproducible.

  10. I suspected Chrome, which often has partially baked additions crop up. So I checked Firefox, which works fine.

    Thanks for the additional confirmation. The true name of this might be Slimming Pain, then. :)

  11. Anyone know if this Chrome issue is affecting different versions of WordPress, or is this just the WordPress 4.3 release?

  12. If one doesn’t want tell all the people that have access to wp-admin to disable “slimming painting” this code added to functions.php could be a work around until an official fix is released:

    add_action(‘admin_enqueue_scripts’, ‘chrome_fix’);
    function chrome_fix() {
    if ( strpos( $_SERVER[‘HTTP_USER_AGENT’], ‘Chrome’ ) !== false )
    wp_add_inline_style( ‘wp-admin’, ‘#adminmenu { transform: translateZ(0); }’ );

  13. This bug is indeed super annoying, but I have a question about your fix. If I disable slimming paint now, when Chrome releases the update will it return my slimming paint settings to normal? I prefer not to have any weird/obscure settings set to abnormal setting like this when it’s not necessary.

  14. Thanks for the post. I thought I had a virus in chrome. You did a great job with the instructions; making it super simple to correct this issue.

  15. Thanks for posting this article, I’ve just started using Word Press and this has been driving me nuts! Simple fix when you know how!

    One this I noticed was there was only One enable option to change (double checked with a CMD + F) but it seems to have worked anyway. Just wondering if there is any reason you know of that would mean I am missing one?

  16. Issue for me as well! I’ve been going crazy because I recently updated to Windows 10 and thought that was the problem!

  17. Thank you for figuring out this detail. Super annoying. Well composed post with screenshots and everything. Keep up the great work!

  18. Thanks for this! I noticed the menus, but on one of my sites I noticed that the pages were displaying incorrectly; elements were repeating and odd colors where interspersed. Once I implemented this fix, ALL of that went away and the site itself was displaying as intended.

  19. Add me to the Mega Thank You list. I was/am going nuts! I thought it was the last version of WP that was the cause and about to send in a ticket.

  20. It’s funny, from the WP forums I had only seen people with Macs complain about this – then it happened to me (Windows), was a little surprised…

  21. Saved me from insanity, i thought my site was on verge of breakdown. Thanks so much for sharing this

  22. Thank you. Working on a new site and it has been driving me crazy. I even reinstalled WordPress a few times. I should have tried a different browser as I never even thought it was chrome.

  23. Thanks a lot Jeff!!!

    I was losing my mind over this, thinking the problem was with my database. Tried almost everything and finally found this post. Thanks a ton buddy!

  24. Note that the Chrome team has found and fixed the bug, and it will be in chrome canary tomorrow. However, it likely well not get pushed into chrome 45, but will be in chrome 46, in a few weeks.

  25. Thank you so much. I expected it to be a chrome error because in firefox everything was alright. But I would have never found the real error itself. So you are the timesaver No. 1 this week!

  26. I’m also seeing that when trying to add a new user the user is pre-populated with the admin information. The css fix doesn’t seem to address this error.

  27. Chrome update: They fast tracked the bug fix. It’s currently scheduled to be released in Chrome 45 (branch 2454) and Chrome 46 (branch 2490) somewhere within 1 week. The fix is in Chrome Canary (47) right now.

  28. Thanks for the post!

    I was launching a website for a client this week, and right as I was supposed to hand the site off to them this started happening and I thought I broke something =/ Wasted like 3 hours troubleshooting and couldn’t for the life of me figure out what was going on

  29. And there is still the issue that a different (red) background for a menu item in the top admin bar is not displayed in Chrome. It does in IE.
    This is used in the lj-maintenance mode plugin.

  30. Hi all! Hi Jeff! Thank you all for this post, the solution and the discussion. Yet…

    I’ve heard or read no one complain about Opera. The Browser. Yet, that’s the one I use, and the issue is exactly the same. I reckon I can wait till my face grows a 3ft beard till that be fixed, right? What do you reckon?

    Kindest regards from the Netherlands

    – – – – – – –

    Part 2:
    After having dealt with this for weeks (I mean, it’s not the end of the world) I’ve found an ugly but easy quick fix, for anyone who still experiences this:

    when your mouse is hovering over the WP admin menu, try zooming in (CTRL-+) and zooming back to normal (CTRL-0) again. That appears to set it all back into place for that moment.

    Yes. A workaround. Ugly. Stupid even. But it works :)

  31. I began to use a WordPress theme called Customizr for a website two months ago but for reasons unknown my preferred browser Chrome (Version 47.0.2526.106 m) has crashed at least three times since then, which led to loss of hours of work. Ever since I switched to Firefox I have never experienced a single crash. A bit digging online turned up evidence that others have had or are having the same problem with Chrome.


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