File:VisRedError1.jpg - Select a section.
File:VisRedError2.jpg - Cut (Shift+Del) and put cursor in...
File:VisRedError3.jpg - ..."New paragraph" area.
File:VisRedError5.jpg - Paste (Shift+Ins). Notice "phantom" text has appeared below normal.
File:VisRedError4.jpg - Put cursor in "phantom" text. It has dissappeared.
File:VisRedError6.jpg - Press Del. Whole text has dissapeared! Uncought errors in browser console.
File:VisRedError7.jpg - Undo didn't work either. More uncought error in browser console.
Found and reproduced in Chrome 64.0.3282.186 / Windows 7 SP1