Fatal Error since WP 5.8 update

@pwizard It looks like some core WP-Optimize files are missing.

Could you please try to de-activate and delete the WP-Optimize plugin and try to install the plugin files via FTP/SFTP?

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.

Tried that. Has not resolved the issue. (want to make it clear it appears site still runs, just the error is in the log)). So I don’t know if this is working as it should.

@pwizard Could you please try to switch your PHP version (upgrade/downgrade) on your server and check it helps to fix the issue?

Rolled back PHP, no change, same error.

@pwizard

Have you performed a conflict test yet?

If not – first, please make a full site backup.

Try deactivating all plugins except for WP-optimize and see if it is resolved.

If so, reactivate each plugin one at a time until you find the culprit. You can check for the issue between activating each plugin, so you can see which one is causing problems.

Please let us know your findings.

It would be virtually impossible to determine this, or would take a long long time. The error is intermittant, I don’t know what triggers it. With a log of plugins, it is time consuming.

Do you have any feedback on what this error might refer to? What it might mean?

@pwizard The error refers to initializing the class, I suspect it should be conflict with one of the plugins installed on your site.