Cannot Update from 3.4.0 to 3.4.2

I tried to replicate the issue, but I was able to update from 3.4.0 to 3.4.2 without any problems. If you’re updating while the plugin is active, try deactivating WP-Optimize first. Once deactivated, proceed with the update and then activate the plugin again after the update is complete. Let me know if this works for you!

I’ve already tried that but no luck.. ??

Can you check your file permissions both for your plugins, the WPO plugin and /FFMpeg.php

They should be 755. Please see here for a guide: https://www.malcare.com/blog/wordpress-file-permissions/

I did what you’ve suggested, all the files and subfolder are having 755 and I still get the same error.
I pretty sure that it’s not a permission problem because I have multiple websites on the server and they all have the same permissions, on some of them it worked, and on a few the update is failing.

Let’s try a more detailed approach to resolve your update issue:

1. Export WP-Optimize Settings:
   • Go to Settings > Export / Import Settings.
   • Click Export to export the WP-Optimize configuration JSON file.
2. Backup Your Site:
   • Ensure you take a complete backup of your site using UpdraftPlus so you can restore it if something goes wrong.
3. Manual Update:
   • Deactivate and delete the current WP-Optimize plugin from your WordPress dashboard (this will not delete your settings).
   • Download the latest version of WP-Optimize from the WordPress repository.
   • Go to Plugins > Add New > Upload Plugin in your WordPress admin.
   • Upload and install the latest version.
4. Import WP-Optimize Settings (if settings are lost):
   • If your settings are lost, you can import them back.
   • Go to Settings > Export / Import Settings.
   • Click Import and upload the JSON file you previously exported.

Please follow these steps and let us know if this resolves your issue.