Steps to reproduce:

1. Create a content item with richtext field
2. In richtext field create 2 lines with text (also, separate them by some empty lines)
3. add image to them by 'Upload image' button
4. Drag  image from one line to the other

Actual result: 

the sliding image disappears when an error occurs in the console

Expected result:

Moving the image should not make it disappear