Xlib: extension "RENDER" missing on display ":0.0". Grabbing the mouse failed with "GrabNotViewable" Xlib: extension "RENDER" missing on display ":0.0". Grabbing the mouse failed with "GrabNotViewable" Grabbing the mouse failed with "GrabNotViewable" Grabbing the mouse failed with "GrabNotViewable" QToolBar::QToolBar main window cannot be 0.