Support » Fixing WordPress » Fatal error after 4.1 Upgrade

  • Resolved ktrueman

    (@ktrueman)


    After running the automatic update on 2 different sites, I get the following error (emphasis mine):

    Fatal error: Call to undefined function wp_json_encode() in “…”/wp-admin/includes/misc.php on line 668

    (I stripped out some path info in between the quotes above)

    Any thoughts ?

Viewing 15 replies - 1 through 15 (of 19 total)
  • Moderator James Huff

    (@macmanx)

    Volunteer Moderator

    Try downloading WordPress again and delete then replace your copies of everything except the wp-config.php file and the /wp-content/ directory with fresh copies from the download. This will effectively replace all of your core files without damaging your content and settings. Some uploaders tend to be unreliable when overwriting files, so don’t forget to delete the original files before replacing them.

    If that doesn’t correct the issue, try manually resetting your plugins (no Dashboard access required). If that resolves the issue, reactivate each one individually until you find the cause.

    If that does not resolve the issue, access your server via FTP or SFTP, navigate to /wp-content/themes/ and rename the directory of your currently active theme. This will force the default theme to activate and hopefully rule-out a theme-specific issue (theme functions can interfere like plugins).

    same issue here, tried everything, when installing wordpress manually and login back in it won’t take me to the update database dialog

    The function “wp_json_encode” is defined in “wp-includes/functions.php” so maybe just replace it from the v4.1 zip file.

    Moderator James Huff

    (@macmanx)

    Volunteer Moderator

    gael.angels, if none of the above worked for you, please open your own thread: https://wordpress.org/support/forum/how-to-and-troubleshooting#postform

    I’m having the same problem. I’ve tried everything suggested here but no love 🙁

    Moderator James Huff

    (@macmanx)

    Volunteer Moderator

    Had the same exact problem. I tried @rossmitchell’s solution and it worked:

    I downloaded a fresh copy of WP 4.1, and replaced the functions.php file. Everything seems to work now, though it’s still prompting me to upgrade.

    It seems like there’s probably more to this error, and since multiple people are having the same issue I’ll probably wait to upgrade until some sort of fix is found.

    I’m having a similiar problem related to the upgrade.

    I could not get the upgrade to 4.1 to work via WordPress’s automatic feature, doing this I got the error that everyone above has been commenting on.

    Thus I went in through my hosting account. There the upgrade appeared to work successfully, but I get this error now when trying to log in:

    Fatal error: Call to undefined function wp_json_encode() in /home/content/29/6593929/html/wp-admin/includes/misc.php on line 668

    I can’t get to my dashboard?

    I got it to work by installing WordPress manually following the step-by-step guide, except instead of renaming my themes folder like James suggested I renamed my plugins folder then went back to login and typed in this url: …./wp-admin/upgrade.php to update files and it did the trick, then I went back and named back the plugins folder

    I think that way went wrong is that I updated plugins first and then WordPress 4.1, because on a bunch of other websites I manage I did the WordPress upgrade first and it didn’t have an issue and then upgraded my plugins

    Moderator James Huff

    (@macmanx)

    Volunteer Moderator

    BottleOfPills, if none of the above worked for you, please open your own thread: https://wordpress.org/support/forum/how-to-and-troubleshooting#postform (and please at least attempt to read the thread before just crashing into it, as you would have seen this already written twice)

    gael.angels, you’re welcome!

    ktrueman, I do apologize that people keep hijacking your thread, probably sending you plenty of unwanted reply notification emails. Please let us know if the above worked for you, of if you’d like to start a new thread, we totally understand.

    Hi James, I’m new to the WP Forum. I can’t understand why you keep asking posters to start their own threads?

    Like, we’re all discussing the same error topic here, why start a new thread? When someone finds a solution, people with the problem know where to come for a solution – here. Why force people to search through lots of other threads?

    What would you suggest we call the new thread? Fatal error after 4.1 Upgrade thread #2

    I’m sure ktrueman doesn’t mind getting lots of reply notification emails. He did finish his post with “Any thoughts ?”

    This fixed my Fatal Error. Thank you!

    @kerryww

    I can’t understand why you keep asking posters to start their own threads?

    Welcome to the WP Forums :)! – please give this a read – http://codex.wordpress.org/Forum_Welcome

    In particular –

    Posting your own topic is smiled upon. Unless you are using the same version of WordPress on the same physical server hosted by the same hosts with the same plugins, theme & configurations as the original poster, do not post in someone else’s thread. Start your own topic.

    Even though it may seem like you have the same issue, it’s unlikely that your site is identical and there are many issues that can cause these kinds of symptoms. Plus, it’s simply very confusing to have multiple conversations in the same thread. So by having your own thread, you’re more likely to get good help and everyone else is too. Thanks :)!

    laurab

    (@laurabrivadera)

    Hi, I have the following error that do not let me accede to my dashboard:

    Fatal error: Call to undefined function wp_json_encode() in /home/u507502189/public_html/wp-includes/theme.php on line 1960

    i installed the wp 4.1 version againg but not config and content files.
    Can you help me? i am not a code professional, thanks

    Andrew Nevins

    (@anevins)

    WCLDN 2018 Contributor | Volunteer support

    @laurabrivadera, you need to open a new thread: https://wordpress.org/support/forum/how-to-and-troubleshooting#postform

    Trust us, we’re not trying to be annoying. It will help you 🙂

Viewing 15 replies - 1 through 15 (of 19 total)
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