Hello Robert,
Apologies for the inconvenience you're experiencing.
The issue you're encountering when trying to upload images in SP Page Builder is caused by a missing PHP extension called GD. This extension is required for image processing and is not currently enabled on your server.
We kindly recommend contacting your hosting provider and asking them to enable the GD extension for PHP. Once it is enabled, the image upload functionality in SP Page Builder should work as expected.
Please let us know if you need any further assistance.
Best regards