Sorry to read your review @dennisoizo. Firstly, before we try to determine what may have caused this, you can deactivate the plugin manually by renaming the plugin directory (wp-content/plugins/performance-lab) using FTP or your hosting control panel’s file manager. Renaming the plugin folder will ensure it’s deactivated.

Please also share what configurations you may have applied within the plugin before you found your site crashed. What may have happened if you enabled the SQLite feature, and your hosting service may not have this configured as required. Alternatively you may have encountered a conflict with a third party plugin. We should be able to determine more on this once you site is live.

Let me know how you get on after performing the above, or ask if you have any questions.