The customer observed that pasting content from an external editor (e.g. TextEdit, Word) into itemized/ordered list in RichText ends up with the editor being unable to save draft or publish the content.
Steps to reproduce:
1. Create a new article
2. Insert an itemized/ordered list into the RichText
3. Copy some text from an external editor (observed using TextEdit and Word) as a new position on the list.
4. Hit "Save" or "Publish".
User is presented with an error: