Message # 1
My website contains many Gif images of my drawings with up to ten of them on each page.
A typical line of HTML code was
<IMG alt="Legless Mermaid" src="$IMG_URL3$" width=622 height=492>
I did some edits to the page (not related to the above image) and when I saved it, all the pictures on the page have vanished. They have been replaced by icons and labels (such as "Legless Mermaid" in the above example). Furthermore, all the IMG statements had been automatically expanded to include a more specific reference, for example:
<IMG alt="Legless Mermaid" src="<!--IMG_URL3-->/_si/0/19288930.gif<!--IMG_URL3-->" width=622 height=492>
I don't know whether the Edit facility has suddenly changed or whether it is trying (unsuccessfully) to respond to a change in HTML.
Message # 2
It looks like you edit your pages by using Visual Editor but I dont know which module the error happened, so I cannot provide the solution.
Message # 3
My problem has suddenly gone away. I don't know whether it was a temporary technical glitch or whether Technical Support found a solution.