Replace Summernote (default opencart html editor) with CKEditor.
Tested to be working on category, information, product and works with all email template extension changes (order/return status updates and newsletter).
This is a default build of CKEditor with minified plugins so that it loads fast.
We've not seen this before but it sounds like a browser issue. Best to check your browers error console to see if there's anything missing or error from another plugin/etc.
If you require custom support please open a support ticket and we can help you resolve this issue:
https://support.opencart-templates.co.uk/
If you require custom support please open a support ticket and we can help you resolve this issue:
https://support.opencart-templates.co.uk/