Title: Fatal error when reactivates performance lab plugin Last modified: March 10, 2023 --- # Fatal error when reactivates performance lab plugin * Resolved [onlionentertainment](https://wordpress.org/support/users/onlionentertainment/) * (@onlionentertainment) * [3 years, 3 months ago](https://wordpress.org/support/topic/fatal-error-when-reactivates-performance-lab-plugin/) * First I Installed the Plugin: Performance Lab and then deactivated it to test speed of website. Then again I wanted to re activate it. But while re activating it I got below issue. How to solve this? Since my website is down and showing fatal error when I accessed it. * Error : **Fatal error**: Cannot redeclare perflab_load_server_timing_api_from_dropin()( previously declared in /home/……/public_html/wp-content/object-cache.php:43) in**/ home/……/public_html/wp-content/object-cache-plst-orig.php** on line **42** * The page I need help with: _[[log in](https://login.wordpress.org/?redirect_to=https%3A%2F%2Fwordpress.org%2Fsupport%2Ftopic%2Ffatal-error-when-reactivates-performance-lab-plugin%2F%3Foutput_format%3Dmd&locale=en_US) to see the link]_ Viewing 8 replies - 1 through 8 (of 8 total) * Thread Starter [onlionentertainment](https://wordpress.org/support/users/onlionentertainment/) * (@onlionentertainment) * [3 years, 3 months ago](https://wordpress.org/support/topic/fatal-error-when-reactivates-performance-lab-plugin/#post-16545952) * Any help I cant access my wordpress backend and production site also. Both are inaccessible. - This reply was modified 3 years, 3 months ago by [onlionentertainment](https://wordpress.org/support/users/onlionentertainment/). * Plugin Support [James Osborne](https://wordpress.org/support/users/jamesosborne/) * (@jamesosborne) * [3 years, 3 months ago](https://wordpress.org/support/topic/fatal-error-when-reactivates-performance-lab-plugin/#post-16546771) * Thanks for reaching out [@onlionentertainment](https://wordpress.org/support/users/onlionentertainment/), and sorry to hear you’ve been encountering problems re-activating the plugin. * As you’re unable to access your front end or wp-admin panel, let’s first of all deactivate the Performance Lab plugin manually. You’ll need FTP or file manager access to do so. In order to do this, please navigate to `wp-content/plugins`. From there please delete or rename the `performance-lab` directory, * Let me know if you’re able to access your site once more after performing the above, or ask if you have any questions with the above. * Plugin Support [James Osborne](https://wordpress.org/support/users/jamesosborne/) * (@jamesosborne) * [3 years, 3 months ago](https://wordpress.org/support/topic/fatal-error-when-reactivates-performance-lab-plugin/#post-16547935) * Hi [@onlionentertainment](https://wordpress.org/support/users/onlionentertainment/), * I’m just following up with you to ensure all is good with your site and you’re able to access it as normal? From my side your site is accessible at present. * Thread Starter [onlionentertainment](https://wordpress.org/support/users/onlionentertainment/) * (@onlionentertainment) * [3 years, 3 months ago](https://wordpress.org/support/topic/fatal-error-when-reactivates-performance-lab-plugin/#post-16548039) * Hey James * Fortunately there was a backup. I asked my domain hosting provider to restore. They restored. Every thing is normal now. But genuinely there is a issue with this plugin that’s creating conflict with others. Please look into.since i installed performance lab just because Google insights dev suggested. Otherwise I couldn’t. So reputation is very much important. * Plugin Support [James Osborne](https://wordpress.org/support/users/jamesosborne/) * (@jamesosborne) * [3 years, 3 months ago](https://wordpress.org/support/topic/fatal-error-when-reactivates-performance-lab-plugin/#post-16548206) * Glad to hear you were able to get your site back up and running, appreciate the update. * > But genuinely there is a issue with this plugin that’s creating conflict with > others. Please look into.since i installed performance lab just because Google > insights dev suggested.  * Based on the insights you reported with, it sounds like another plugin created it’s own **object-cache.php** file, prior to the Performance Lab generated file. If you’d like to share any optimization features at host level, or plugins other than WP Rocket, which it looks like you have active, I’d be happy to do some testing. We are [considering changes](https://github.com/WordPress/performance/issues/630) to how the plugin handles multiple object-cache.php file additions, although we haven’t heard of similar conflicts so far to what you’ve reported. * Let me know if you have any questions with the above. * Plugin Support [Felix Arntz](https://wordpress.org/support/users/flixos90/) * (@flixos90) * [3 years, 3 months ago](https://wordpress.org/support/topic/fatal-error-when-reactivates-performance-lab-plugin/#post-16548774) * Thank you for raising this ticket. I just added a note to our tracking issue where I’m working on a fix for the drop-in compatibility issues: [https://github.com/WordPress/performance/issues/630](https://github.com/WordPress/performance/issues/630) * We aim to get this solved for the upcoming release. * Plugin Support [James Osborne](https://wordpress.org/support/users/jamesosborne/) * (@jamesosborne) * [3 years, 2 months ago](https://wordpress.org/support/topic/fatal-error-when-reactivates-performance-lab-plugin/#post-16581444) * [@onlionentertainment](https://wordpress.org/support/users/onlionentertainment/) We’ve just released the latest version of the plugin, which has a fix in place for this. Can you update is not already done so, and share whether all works as expected? Thanks for reporting this. * Plugin Support [James Osborne](https://wordpress.org/support/users/jamesosborne/) * (@jamesosborne) * [3 years ago](https://wordpress.org/support/topic/fatal-error-when-reactivates-performance-lab-plugin/#post-16749124) * As we didn’t receive a response I’ll mark this as resolved. Feel free to open a new support topic if you continue to encounter issues, or reopen this topic and we’d be happy to assist. Viewing 8 replies - 1 through 8 (of 8 total) The topic ‘Fatal error when reactivates performance lab plugin’ is closed to new replies. * ![](https://ps.w.org/performance-lab/assets/icon.svg?rev=2787149) * [Performance Lab](https://wordpress.org/plugins/performance-lab/) * [Frequently Asked Questions](https://wordpress.org/plugins/performance-lab/#faq) * [Support Threads](https://wordpress.org/support/plugin/performance-lab/) * [Active Topics](https://wordpress.org/support/plugin/performance-lab/active/) * [Unresolved Topics](https://wordpress.org/support/plugin/performance-lab/unresolved/) * [Reviews](https://wordpress.org/support/plugin/performance-lab/reviews/) * 8 replies * 3 participants * Last reply from: [James Osborne](https://wordpress.org/support/users/jamesosborne/) * Last activity: [3 years ago](https://wordpress.org/support/topic/fatal-error-when-reactivates-performance-lab-plugin/#post-16749124) * Status: resolved