Title: PHP errors caused by WP-Optimize Last modified: July 20, 2021 --- # PHP errors caused by WP-Optimize * Resolved [denny_p](https://wordpress.org/support/users/denny_p/) * (@denny_p) * [5 years, 1 month ago](https://wordpress.org/support/topic/php-errors-caused-by-wp-optimize/) * Hello madam or sir, * All of a sudden, my WP-Optimize is causing (seems to cause) PHP errors. Please see below an error from my log file. There are 1000 of these lines in my error log. * `Uncaught Error: Call to undefined function WP_Optimize() in /home/u51255p58880/ domains/XXXXX.COM/public_html/wp-content/plugins/wp-optimize/cache/file-based- page-cache-functions.php:178\nStack trace:\n#0 [internal function]: wpo_cache(' ...', 9)\n#1 /home/u51255p58880/domains/XXXXX.COM/public_html/ wp-includes/functions.php(4757): ob_end_flush()\n#2 /home/u51255p58880/domains/ XXXXX.COM/public_html/wp-includes/class-wp-hook.php(292): wp_ob_end_flush_all('')\ n#3 /home/u51255p58880/domains/XXXXX.COM/public_html/wp-includes/class-wp-hook. php(316): WP_Hook->apply_filters(NULL, Array)\n#4 /home/u51255p58880/domains/ XXXXX.COM/public_html/wp-includes/plugin.php(484): WP_Hook->do_action(Array)\ n#5 /home/u51255p58880/domains/XXXXX.COM/public_html/wp-includes/load.php(1072): do_action('shutdown')\n#6 [internal function]: shutdown_action_hook()\n#7 {main}\ n thrown in /home/u51255p58880/domains/XXXXX.COM/public_html/wp-content/plugins/ wp-optimize/cache/file-based-page-cache-functions.php on line 178\n, referer: https://www.XXXXX.COM/` * Only after completely removing the plugin, the errors stopped. So, only disabling the plugin did not help. Can you please advise what is causing this errors? * Thanks in advance! * Denny Viewing 3 replies - 1 through 3 (of 3 total) * [Harshad](https://wordpress.org/support/users/bornforphp/) * (@bornforphp) * [5 years, 1 month ago](https://wordpress.org/support/topic/php-errors-caused-by-wp-optimize/#post-14682713) * [@denny_p](https://wordpress.org/support/users/denny_p/) `It looks like some core WP-Optimize files are missing. * Can you please upload the plugin via FTP/SFTP instead? * To do this: * 1. Unzip the WP-Optimize ZIP on your local machine, using a zip utility such as 7-zip. 2. Access your WordPress installation via FTP or your host’s filemanager. 3. Navigate to wp-content/plugins. Upload the WP-Optimize folder here. 4. Go to the Plugins page on your WordPress dashboard. You should see WP-Optimize in the list of plugins. * Let us know if above steps helps to fix the issue? * Thread Starter [denny_p](https://wordpress.org/support/users/denny_p/) * (@denny_p) * [5 years, 1 month ago](https://wordpress.org/support/topic/php-errors-caused-by-wp-optimize/#post-14684191) * Hello Harshad, * I hoped this was the issue (as the site was just moved by hoster from VPS to dedicated server), but unfortunately, after uploading via FTP and activating the plugin, I got the same errors again: * ``` [Wed Jul 21 12:48:03.290812 2021] [lsapi:error] [pid 29948:tid 140532469606144] [client 2a02:a210:d21:a180:8ce9:ad72:26b5:2960:52976] [host www.XXXX.COM] Backend fatal error: PHP Fatal error: Uncaught Error: Call to undefined function wp_cache_get() in /home/u51255p58880/domains/XXXX.COM/public_html/wp-includes/option.php:97\nStack trace:\n#0 /home/u51255p58880/domains/XXXX.COM/public_html/wp-includes/l10n.php(63): get_option('WPLANG')\n#1 /home/u51255p58880/domains/XXXX.COM/public_html/wp-includes/l10n.php(137): get_locale()\n#2 /home/u51255p58880/domains/XXXX.COM/public_html/wp-includes/l10n.php(1278): determine_locale()\n#3 /home/u51255p58880/domains/XXXX.COM/public_html/wp-includes/l10n.php(1240): _get_path_to_translation_from_lang_dir('wp-optimize')\n#4 /home/u51255p58880/domains/XXXX.COM/public_html/wp-includes/l10n.php(1210): _get_path_to_translation('wp-optimize')\n#5 /home/u51255p58880/domains/XXXX.COM/public_html/wp-includes/l10n.php(1308): _load_textdomain_just_in_time('wp-optimize')\n#6 /home/u51255p58880/domains/XXXX.COM/public_html/wp-includes/l10n.php(177): get_translations_for_domain('wp-optimize')\n#7 /home/u51255p58880/domains/pokemo in /home/u51255p58880/domains/XXXX.COM/public_html/wp-includes/option.php on line 97\n, referer: https://www.XXXX.COM/ [Wed Jul 21 12:48:07.962084 2021] [lsapi:error] [pid 29948:tid 140532410857216] [client 2a02:a210:a143:ac80:c495:4347:a12d:dc80:55017] [host www.XXXX.COM] Backend fatal error: PHP Fatal error: Uncaught Error: Call to undefined function wp_cache_get() in /home/u51255p58880/domains/XXXX.COM/public_html/wp-includes/option.php:97\nStack trace:\n#0 /home/u51255p58880/domains/XXXX.COM/public_html/wp-includes/l10n.php(63): get_option('WPLANG')\n#1 /home/u51255p58880/domains/XXXX.COM/public_html/wp-includes/l10n.php(137): get_locale()\n#2 /home/u51255p58880/domains/XXXX.COM/public_html/wp-includes/l10n.php(1278): determine_locale()\n#3 /home/u51255p58880/domains/XXXX.COM/public_html/wp-includes/l10n.php(1240): _get_path_to_translation_from_lang_dir('wp-optimize')\n#4 /home/u51255p58880/domains/XXXX.COM/public_html/wp-includes/l10n.php(1210): _get_path_to_translation('wp-optimize')\n#5 /home/u51255p58880/domains/XXXX.COM/public_html/wp-includes/l10n.php(1308): _load_textdomain_just_in_time('wp-optimize')\n#6 /home/u51255p58880/domains/XXXX.COM/public_html/wp-includes/l10n.php(177): get_translations_for_domain('wp-optimize')\n#7 /home/u51255p58880/domains/pokemo in /home/u51255p58880/domains/XXXX.COM/public_html/wp-includes/option.php on line 97\n [Wed Jul 21 12:48:11.643294 2021] [lsapi:error] [pid 27984:tid 140532436035328] [client 2a02:a210:2683:8f00:95ea:2b48:2bc3:3256:57993] [host www.XXXX.COM] Backend fatal error: PHP Fatal error: Uncaught Error: Call to undefined function wp_cache_get() in /home/u51255p58880/domains/XXXX.COM/public_html/wp-includes/option.php:97\nStack trace:\n#0 /home/u51255p58880/domains/XXXX.COM/public_html/wp-includes/l10n.php(63): get_option('WPLANG')\n#1 /home/u51255p58880/domains/XXXX.COM/public_html/wp-includes/l10n.php(137): get_locale()\n#2 /home/u51255p58880/domains/XXXX.COM/public_html/wp-includes/l10n.php(1278): determine_locale()\n#3 /home/u51255p58880/domains/XXXX.COM/public_html/wp-includes/l10n.php(1240): _get_path_to_translation_from_lang_dir('wp-optimize')\n#4 /home/u51255p58880/domains/XXXX.COM/public_html/wp-includes/l10n.php(1210): _get_path_to_translation('wp-optimize')\n#5 /home/u51255p58880/domains/XXXX.COM/public_html/wp-includes/l10n.php(1308): _load_textdomain_just_in_time('wp-optimize')\n#6 /home/u51255p58880/domains/XXXX.COM/public_html/wp-includes/l10n.php(177): get_translations_for_domain('wp-optimize')\n#7 /home/u51255p58880/domains/pokemo in /home/u51255p58880/domains/XXXX.COM/public_html/wp-includes/option.php on line 97\n, referer: https://www.XXXX.COM/page/2/?s=Charizard&post_type=product&dgwt_wcas=1 ``` * Any other ideas maybe? Thanks in advance! Best, Denny * [Harshad](https://wordpress.org/support/users/bornforphp/) * (@bornforphp) * [5 years, 1 month ago](https://wordpress.org/support/topic/php-errors-caused-by-wp-optimize/#post-14687397) * [@denny_p](https://wordpress.org/support/users/denny_p/) Do you have any other cache plugin installed, or have cache mechanism on your server? If yes, could you please temporarily disable it and check if you still get the errors? Viewing 3 replies - 1 through 3 (of 3 total) The topic ‘PHP errors caused by WP-Optimize’ is closed to new replies. * ![](https://ps.w.org/wp-optimize/assets/icon-256x256.png?rev=1552899) * [WP-Optimize – Cache, Compress images, Minify & Clean database to boost page speed & performance](https://wordpress.org/plugins/wp-optimize/) * [Frequently Asked Questions](https://wordpress.org/plugins/wp-optimize/#faq) * [Support Threads](https://wordpress.org/support/plugin/wp-optimize/) * [Active Topics](https://wordpress.org/support/plugin/wp-optimize/active/) * [Unresolved Topics](https://wordpress.org/support/plugin/wp-optimize/unresolved/) * [Reviews](https://wordpress.org/support/plugin/wp-optimize/reviews/) ## Tags * [php](https://wordpress.org/support/topic-tag/php/) * 3 replies * 2 participants * Last reply from: [Harshad](https://wordpress.org/support/users/bornforphp/) * Last activity: [5 years, 1 month ago](https://wordpress.org/support/topic/php-errors-caused-by-wp-optimize/#post-14687397) * Status: resolved