Compatibility update: Firefox 38 and 38.0.5

Following up on my previous post on Firefox 38 compatibility, I wanted to highlight an important change that I missed: in-content preferences. The preferences window is no more, and instead the main preferences UI is shown in a new tab. This only affects add-ons that overlay the preferences window, which should be rare.

Additionally, there’s an out-of-cycle release planned for June 2nd, which will go with version number 38.0.5. This is 38 with a few additions, which you can see in the release notes. These additions shouldn’t conflict with extensions compatible with 38, but it could conflict with complete themes. The new release is now available in the beta channel, so we recommend you test your add-ons on that version.

29 comments on “Compatibility update: Firefox 38 and 38.0.5”

  1. Kohei Yoshino wrote on

    Japanese translation:

    1. Jorge Villalobos wrote on


  2. addon dev wrote on

    When will the extension signing come in to effect. I thought it was expected for version 38.

    1. Jorge Villalobos wrote on

      The current plan is to enable it in Firefox 40. The latest info will always be in this doc.

  3. Karol Olkowski wrote on

    I do not like the preferences window being limited to a tab. Why is Firefox trying to be like Google Chrome? I use Firefox for a reason. I’m still disappointed that the reload button is stuck in the URL field and no longer on the left-hand side. (I know I can install an extension to get that functionality back, but I’d rather keep the number of extensions to a minimum. This is functionality that shouldn’t have been removed.)

  4. Karol Olkowski wrote on

    I’ve found the hack in about:config that disables this functionality that is very frustrating to me, so I’m happy. I hope that this ability is not denied from the user in future Firefox releases.

  5. steve jobs unkle from his mother wrote on

    i just wanna say firefox 38.05 is so fuckin buggy n messed up just give up and admit u been defeeted by Internet Explorer

  6. Peer wrote on

    Even on my 4k 40″ display, the new preference UI is barely legible, all fonts are way too small. and the UI is as bad for people who wear glasses as the iOs 6 to 7 transition practically killed the useability of Apple products for me. Does none of the testers ever wear glasses? FF 38 useability is much lower compared to the old UI, even for people with mild visual defects.

  7. Len wrote on

    Firefox just updated itself to 38.0.5, and my toolbars are now totally messed up and the address window has disappeared. The search window now runs across the entire width of the browser, and the back, forward, and menu buttons have vaporized. Is there a simple fix, or way to roll back to the old version??

    1. Jorge Villalobos wrote on

      If you click on the last button of the toolbar and then click on the Customize button at the bottom, you should be able to reset your toolbars to the default, or add/move/remove whatever you want.

  8. Mick Russom wrote on

    Preferences changes stink. Firefox is becoming a bloated bad copy of Chrome. 526 on chrome in HTML 5 Test vs 467 in Firefox 38.05. Seems like they are busy shuffling deck chairs on the titantic and alienating users while ignoring HTML 5

  9. Mick Russom wrote on

    Note: firefox blog is now censoring comments.

    1. Jorge Villalobos wrote on

      Our blog has always had moderated comments. Sorry, I don’t check every day for new comments.

  10. Francis Lambert wrote on

    The search engine on Firefox used to be direct. Now with 38.0.5 it appears to go through First, this is highly US orientated which is no good for me in the UK and second, when the back button is pressed the search page content is no longer there. How does one get rid of maxwebsearch?

    1. Jorge Villalobos wrote on

      It sounds like you have some malware on your system. You can find ways to resolve this in our support site.

  11. Greg wrote on

    Overnight Firefox updated to 38.0.5 automatically. this morning on my windows 8 PC it takes forever !!! to load a page and on my XP PC I get an error “Could not find Mozilla runtime” anyone else having such issues?

    1. Nonames wrote on

      Yes. Ver 30.0/5 is a total pos. Totally hangs and has a bad memory leak. Why doesn’t Moz finish their programming work before releasing?

  12. Gene wrote on

    I can not update from 38.0.1 to 38.0.5 though I have updated Firefox many times in the past with the same steps. I get to the point where Firefox needs to be restarted. Then get the message cannot restart Firefox because it is already running. Usually shutdown completes and after the restart the update is applied but not this time. I am running Win7.

  13. S wrote on

    How the F do we stop Firefox forcing updates on us, it makes me detest using Firefox and I’m looking for other options. Updates are all set to off in about config and settings yet somehow this S is forced on me again.

  14. Ellie wrote on

    My computer has updated Firefox automatically but now it won’t even load and says Error: Platform version 38.0.5 is not compatible with minVersion > = 38.0.1 maxVersion < = 38.0.1 This means I've lost all my bookmarks as I have to use Chrome. I've restarted. Any other ideas??

    1. Jorge Villalobos wrote on

      Please visit our support site for help. I suppose that restarting in Safe Mode is the best first step, to determine if the problem is caused by a broken add-on.

  15. MAtt wrote on

    This 38.0.5 version is a total mess. And I choose respectfully my words because my frustration go way beyong that. Over night the darn night takes forever to load a simple page and Im not talking about video – my god, plz help… I makes 3 days that I’m trying to fix this from you suggestion page and nothing is working still. Again, I will restric the expression of my frustration.

    Chrome is better? It load page? Will be good, better then mozilla.

  16. Mark wrote on

    Can I get “Open in a new window” back? in the right click context menu? I open things in a new windows for a reason as I write across multiples sites and having to locate which tab when I sometimes have 14 or more windows open while I am sourcing my posts and the TABS, make it take much longer and almost impossible for me to write.

    I use tabs on a few sites but mostly I use open in a new window but that option is no longer available, nor can I find ANY reference on how to turn Tabbed Browsing off so I can regain that functionality.

    You took what I had setup as my preferred options and screwed it up so I cannot navigate as easily and now my computer and Firefox needs to be restarted multiple times to keep from bogging down my system.

    1. Jorge Villalobos wrote on

      I can see the Open Link in New Window option in the context menu. Maybe you have an add-on that hides it?

  17. Fernando wrote on

    Firefox 38.0.5 does not start if you install it on a custom location.

  18. Karen wrote on

    Upgraded to 38.0.5 on my CentOS 6.5 system because I needed a new JRE for a KVM. Now, firefox has no search and doesn’t know what to do with any of the file types. When I right click on a link, it doesn’t open in a new tab or new window, just ignores the click. And it seems to not know it’s a link because it gives me all the image options, etc. Please help – it is unworkable.

    1. Jorge Villalobos wrote on

      Please visit our support site for help.

  19. KC wrote on

    I have been re-installing Firefox 38.05 for more days than I’m willing to count. I have followed all sorts of instructions and they have failed. I have no more time to devote to this.

    I’ve now deleted Firefox from my starter bar and will only use the browser in emergencies.

    Please do a PR release when you’ve fixed the problem.

  20. Peter Handley wrote on

    Firefox 38.0.5 no longer works with the BT Openzone wifi hotspot network. Any attempt to sign in gives the following error message: An error occurred during a connection to SSL received a weak ephemeral Diffie-Hellman key in Server Key Exchange handshake message. (Error code: ssl_error_weak_server_ephemeral_dh_key). DO NOT update beyond ff 38.0.1. This error is ALSO present in the latest Pale Moon 25.5, DO NOT update Pale Moon beyond 25.4.1.