Hi there,
Thank you for the information. I did quite a few of the tests and it seems the problem is generated from your environment as I double checked the case on my installation and 2 other online cases and did not have such an issue.
Now the tests that I have done on your installation:
- Double checked for the 3rd party plugin conflict possibility
- Refreshed the Settings > Permalinks
- Changed the Theme from Pro to the standard WordPress Theme and the problem persists (This shows that the problem is not related to our theme)
- Installed the Transient Cleaner plugin, and deleted the transient cache that might have caused the problem, but no effect.
- I accessed your website via FTP and renamed the .htaccess file to .htaccess-back and went to Settings > Permalinks and saved the settings and checked the case to make sure there is no htaccess changes that cause the redirection problem with no effect.
I am out of options now. Please contact your hosting service provider and ask them to help to find out why the URL of the plugin editing screen goes to the 404 page. They may have a better insight of the server settings as that might be the cause of the issue.
Also, I suggest that you have a complete backup of your website and delete the Essential Grid and add it again from Pro > Validation screen for testing purposes.
The final test will be that you move the website to another server and test the case and see if it is caused by server settings or something related to your installation database.
Thank you.