Good morning Peter and welcome back!
Thank you for reaching out to us.
We are sorry to hear about the image upload no longer working on your website.
I would love to help you with this topic.
I believe this might be caused by one of the following:
- A conflict with your caching plugin’s settings. Please temporarily undo all forms of caching, clear the cache and deactivate the plugin to see if that helps.
- There is some form of conflict, either with your theme (or one of its customization) or another plugin
When it comes to that type of issue, it is preferable to troubleshoot in a staging environment if you have one.
A first quick test is to simply temporarily revert back to a default WordPress theme such as twenty-sixteen to see if the issue persists.
The next step would be to go through our testing for conflicts procedure and let us know what you find out.
Basically the goal here is to revert back to a bare WordPress installation to see if the problem persists. It also allows us to pinpoint what the cause of the issue is.
But, before you do that, there are 2 things I would advise:
- Make a backup of your database
- Consider activating a “Maintenance Page” plugin if you are doing this on your live site (to minimize impact on your visitors)
Let me know how that goes.
Geoff B.