Plugin problem on migration

  • Hi all,

    I ran Duplicators to migrate a website to local server. After migration I couldn’t start the Administrator’s login page. A blank page popup with following warning;
    There has been a critical error on this website…..

    Then on its Terminal, in wp-content folder, I run following command to deactivate all plugins
    $ sudo mv plugins plugins_old

    Afterwards the Administrator’s login page starts but after login I found all plugins gone.

    I couldn’t run again on Terminal;
    $ sudo mv plugins_old plugins

    The above blank page popup again with same warning.

    Please advise how to find out which plugin causes this problem? Is it to reinstall them one-by-one?

    Installed plugins:
    Advanced Editor Tools
    All-in-One WP Migration
    All-in-One WP Migration File Extension
    Cimy Header Image Rotator
    Classic Editor
    Contact Form 7
    Duplicator
    Google Language Translator
    Limit Login Attempts Reloaded
    Wordfence Security
    WP Super Cache

    Thanks in advance

    Regards

    • This topic was modified 1 year, 6 months ago by Yui.
    • This topic was modified 1 year, 6 months ago by Jan Dembowski. Reason: Moved to Fixing WordPress, this is not an Everything else WordPress topic
Viewing 9 replies - 1 through 9 (of 9 total)

  • The reason for the error should be visible in the error log. You can find it in your hosting area. If necessary, the support of your hosting can help you.

    Alternatively, you could also enable debugging in WordPress. How to do this is described here: https://www.ads-software.com/support/article/debugging-in-wordpress/ – also here the support of your hosting can help you if necessary to edit the file accordingly.

    This is the fastest way to find the plugin that is causing the problem.

    Thread Starter satimis

    (@satimis)

    Hi threadi,

    Thanks for your advice.

    I migrate the live site to local server on a VM of Oracle VirtualBox, running LAMP on Ubuntu 22.04 desktop as Operating System.

    I have done the steps already, following your link, but I couldn’t find debug.log on the server. I don’t have cPanel installed.

    In the past I have done this kind of migration using Duplicator for more than 10 years without problem. The problem encountered by me only happened recently.

    I don’t know WHY ?

    Regards

    The debug.log should be located in the wp-content directory. To find it you need e.g. FTP access to your VM. A cPanel installation is not necessary at all.

    Thread Starter satimis

    (@satimis)

    Hi threadi,

The Ubuntu 22.04 VM is running on my desktop computer. I can login and browse its contents.

There are 5 WP sites installed and running on this VM on;

/var/www/html/ (folder)
    classic
    diet
    piano1
    piano2
    piano3

classic, diet and piano3 sites were installed on Duplicator packages, created on their live sites.

I was unable successfully to install piano1 with its Duplicator packages created on its live site. I have to install them on Ubuntu 20.04 VM first, re-created new Duplicator packages and then install its new Duplicator packages on this Ubuntu 22.04 VM.

I'm unable successfully to install piano2 on both Ubuntu 20.04 VM and Ubuntu 22.04 VM with the Duplicator packages created on its live site.

I have been running Duplicator to migrate live sites on Ubuntu 20.04 and 22.04 VMs
    respectively for long time without problem. The problem just happens recently.

On browser running https://local_ip/piano2/
    popup;
    There has been a critical error on this website……

Sorry I can't find debug.log on /wp-content/ folder

Version of PHP
    20.04 VM - 7.4
    22.04 VM - 8.1

Regards

    You need to find the cause in any case a log file in which the error is logged. If debug.log is not present, it could be a major system error that is not getting through to WordPress. This should be found in a system error log. Where this is located depends on your system and its individual setup.

    Thread Starter satimis

    (@satimis)

    Hi threadi,

    The live website piano2 is running on Internet without problem.

    It is very strange to me. I couldn’t find error.log running following command on Terminal;

    $ sudo find /var/www/html/piano2/ | grep error.log
    no output

    Following line is on wp-config.php
    define( ‘WP_DEBUG’, false );

    I change it as;
    define( ‘WP_DEBUG’, true );

    Still no debug.log found

    Regards

    • This reply was modified 1 year, 6 months ago by satimis.
    Thread Starter satimis

    (@satimis)

    Hi threadi,

    Just browse https://local_ip/piano/ on Firefox, following warning popup:-

    Deprecated: strlen(): Passing null to parameter #1 ($string) of type string is deprecated in /var/www/html/piano2/wp-content/plugins/wordfence/vendor/wordfence/wf-waf/src/lib/utils.php on line 479

    Deprecated: strlen(): Passing null to parameter #1 ($string) of type string is deprecated in /var/www/html/piano2/wp-content/plugins/wordfence/vendor/wordfence/wf-waf/src/lib/utils.php on line 479

    Fatal error: Uncaught Error: Call to undefined function mb_strtolower() in /var/www/html/piano2/wp-content/mu-plugins/endurance-page-cache.php:374 Stack trace: #0 /var/www/html/piano2/wp-content/mu-plugins/endurance-page-cache.php(498): Endurance_Page_Cache->to_snake_case() #1 /var/www/html/piano2/wp-includes/class-wp-hook.php(308): Endurance_Page_Cache->option_handler() #2 /var/www/html/piano2/wp-includes/class-wp-hook.php(332): WP_Hook->apply_filters() #3 /var/www/html/piano2/wp-includes/plugin.php(517): WP_Hook->do_action() #4 /var/www/html/piano2/wp-includes/option.php(581): do_action() #5 /var/www/html/piano2/wp-includes/option.php(1830): update_option() #6 /var/www/html/piano2/wp-includes/option.php(1400): update_network_option() #7 /var/www/html/piano2/wp-content/plugins/wordfence/lib/wordfenceClass.php(2351): update_site_option() #8 /var/www/html/piano2/wp-includes/class-wp-hook.php(308): wordfence::veryFirstAction() #9 /var/www/html/piano2/wp-includes/class-wp-hook.php(332): WP_Hook->apply_filters() #10 /var/www/html/piano2/wp-includes/plugin.php(517): WP_Hook->do_action() #11 /var/www/html/piano2/wp-settings.php(486): do_action() #12 /var/www/html/piano2/wp-config.php(189): require_once(‘…’) #13 /var/www/html/piano2/wp-load.php(50): require_once(‘…’) #14 /var/www/html/piano2/wp-blog-header.php(13): require_once(‘…’) #15 /var/www/html/piano2/index.php(17): require(‘…’) #16 {main} thrown in /var/www/html/piano2/wp-content/mu-plugins/endurance-page-cache.php on line 374

    Notice: Function is_embed was called incorrectly. Conditional query tags do not work before the query is run. Before then, they always return false. Please see Debugging in WordPress for more information. (This message was added in version 3.1.0.) in /var/www/html/piano2/wp-includes/functions.php on line 5865

    Notice: Function is_search was called incorrectly. Conditional query tags do not work before the query is run. Before then, they always return false. Please see Debugging in WordPress for more information. (This message was added in version 3.1.0.) in /var/www/html/piano2/wp-includes/functions.php on line 5865

    There has been a critical error on this website.

    Learn more about troubleshooting WordPress.

    The error message

    Call to undefined function mb_strtolower

    is the reason for the problem. Your server installation is missing the mbstring module. How to install it on an Ubuntu system is described e.g. here: https://tecadmin.net/how-to-install-php-on-ubuntu-22-04/

    If you need further help with this, please contact an Ubuntu community.

    The deprecated messages about it concern the WordFence plugin. This indicates that the plugin is not compatible with the PHP version you are using. You should ask questions about this to WordFence support: https://www.ads-software.com/support/plugin/wordfence/

    • This reply was modified 1 year, 6 months ago by threadi.
    Thread Starter satimis

    (@satimis)

    Hi threadi,

    Now I found out the cause of the problem. Please see my another posting:-

    The culprit causing me problem to migrate website endurance-page-cache.php is t….
    https://www.ads-software.com/support/topic/the-culprit-causing-me-problem-to-migrate-website-endurance-page-cache-php-is-t/#post-16771567

    According to my recollection, at time I installed following plugin;
    WP Super Cache

    after install -> activate

    It required further action to register in order making this plugin to work. All other plugins which I installed in the past didn’t require this action. I suspect on further registration it added those 2 packages and creating mu-plugins folder simultaneously.

    Anyway, lot of thanks for your advice to help me.

    Regards

Viewing 9 replies - 1 through 9 (of 9 total)
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