This is an usability issue in editor. reproduce procedure: 1. file:new:blank page 2. click the "number list" icon 3. type abcdef [return] ijlkmn[return] lmnsop[return] you should see the following 1. abcdef 2. ijkmn 3. lmnsop 4. now you put your cursor into 2. ijkmn 5. accidentially, the user click on the "number list" icon again the "2. ijkmn" become no list "ijkmn" From this point, execpt "Undo", there are no way user can recover the error. If user click on the "number list" icon again, it will become 1. abcdef 1. ijkmn 1. lmnsop There are no way that user can "delete something" to join these 3 list together again.
well, yes there is, but it may not be that easy to discover: you would highlight all items and select the list icon once to unnumber the items and then again to renumber. The correct way to recover is to select undo.