- Create a backup of your website.
- Install and activate the WP Downgrade plugin (FREE).
- Go to Settings > WP Downgrade.
- In the WordPress Target Version box, enter the WordPress version you would like to rollback to. (Note: You can use the WP Releases link to find the exact version numbers available.).
- Save Changes.
- Click on the Up-/Downgrade Core button or the Update Core link.
- Click the Re-install Now button.
- Remove the WP Downgrade plugin.
At this point, you should be on the core WordPress version that is known to fix the issue you were having.
Be sure to thoroughly test everything again and if any issues are discovered, you have the backup that was created prior to starting this process.