Viewer disapear

v 0.10.0  / Windows 7 
In "Editor/Viewer" mode
I write 
## Header 2 
Typing 2 dashes with keyboard  -> The "viewer" disappear.
I must go to view / mode again to enable it again.

If I write 
"Header 2"
then select that text, then select "header 2" into the quick help on the left side -> viewer does NOT disappear (no problem in that case)