When creating new Knowledge page, users cannot add attachments to KB document through icon on HTML editor.
Steps to Reproduce
1) Create a KB article in HI
2) Click on "insert/edit image" icon
3) For "type", I selected "attachment" (I have also tried "image library, but didn't work)
4) Browse and choose the image file
5) Click "ok"
6) Image tries to load, but gets stuck in the loading loop
If you drag and drop images in the HTML field, this popup message will not appear.
Related Problem: PRB722212