title: VNC only displaying the mouse cursor but nothing else
body: <p>I have a RaspberryPi with Raspbian and <code>x11vnc</code> installed. I can:</p>
  
  <ul>
  <li><code>startx &amp;</code></li>
  <li><code>x11vnc -usepw -background</code></li>
  </ul>
  
  <p>And then connect to the VNC Server using my Mac. However, after some event (it used to work at some point), the VNC Server only displays a black screen.</p>
  
  <p>I can connect to the RPI using SSH but I can't attach a screen at the moment, because I don't have one.</p>
  
  <p>How do I get the X11vnc Server to display the actual screen again?</p>
  
  <p>The output when I start the server</p>
  
  <pre><code>03/02/2014 18:38:59 -usepw: found /home/pi/.vnc/passwd
  03/02/2014 18:38:59 x11vnc version: 0.9.13 lastmod: 2011-08-10  pid: 5589
  03/02/2014 18:38:59 XOpenDisplay("") failed.
  03/02/2014 18:38:59 Trying again with XAUTHLOCALHOSTNAME=localhost ...
  03/02/2014 18:38:59 
  03/02/2014 18:38:59 *** XOpenDisplay failed. No -display or DISPLAY.
  03/02/2014 18:38:59 *** Trying ":0" in 4 seconds.  Press Ctrl-C to abort.
  03/02/2014 18:38:59 *** 1 2 
  3 4 
  03/02/2014 18:39:03 *** XOpenDisplay of ":0" successful.
  03/02/2014 18:39:03 
  03/02/2014 18:39:03 Using X display :0
  03/02/2014 18:39:03 rootwin: 0x43 reswin: 0xa00001 dpy: 0xe86250
  03/02/2014 18:39:03 
  03/02/2014 18:39:03 ------------------ USEFUL INFORMATION ------------------
  03/02/2014 18:39:03 X DAMAGE available on display, using it for polling hints.
  03/02/2014 18:39:03   To disable this behavior use: '-noxdamage'
  03/02/2014 18:39:03 
  03/02/2014 18:39:03   Most compositing window managers like 'compiz' or 'beryl'
  03/02/2014 18:39:03   cause X DAMAGE to fail, and so you may not see any screen
  03/02/2014 18:39:03   updates via VNC.  Either disable 'compiz' (recommended) or
  03/02/2014 18:39:03   supply the x11vnc '-noxdamage' command line option.
  03/02/2014 18:39:03 
  03/02/2014 18:39:03 Wireframing: -wireframe mode is in effect for window moves.
  03/02/2014 18:39:03   If this yields undesired behavior (poor response, painting
  03/02/2014 18:39:03   errors, etc) it may be disabled:
  03/02/2014 18:39:03    - use '-nowf' to disable wireframing completely.
  03/02/2014 18:39:03    - use '-nowcr' to disable the Copy Rectangle after the
  03/02/2014 18:39:03      moved window is released in the new position.
  03/02/2014 18:39:03   Also see the -help entry for tuning parameters.
  03/02/2014 18:39:03   You can press 3 Alt_L's (Left "Alt" key) in a row to 
  03/02/2014 18:39:03   repaint the screen, also see the -fixscreen option for
  03/02/2014 18:39:03   periodic repaints.
  03/02/2014 18:39:03 
  03/02/2014 18:39:03 XFIXES available on display, resetting cursor mode
  03/02/2014 18:39:03   to: '-cursor most'.
  03/02/2014 18:39:03   to disable this behavior use: '-cursor arrow'
  03/02/2014 18:39:03   or '-noxfixes'.
  03/02/2014 18:39:03 using XFIXES for cursor drawing.
  03/02/2014 18:39:03 GrabServer control via XTEST.
  03/02/2014 18:39:03 
  03/02/2014 18:39:03 Scroll Detection: -scrollcopyrect mode is in effect to
  03/02/2014 18:39:03   use RECORD extension to try to detect scrolling windows
  03/02/2014 18:39:03   (induced by either user keystroke or mouse input).
  03/02/2014 18:39:03   If this yields undesired behavior (poor response, painting
  03/02/2014 18:39:03   errors, etc) it may be disabled via: '-noscr'
  03/02/2014 18:39:03   Also see the -help entry for tuning parameters.
  03/02/2014 18:39:03   You can press 3 Alt_L's (Left "Alt" key) in a row to 
  03/02/2014 18:39:03   repaint the screen, also see the -fixscreen option for
  03/02/2014 18:39:03   periodic repaints.
  03/02/2014 18:39:03 
  03/02/2014 18:39:03 XKEYBOARD: number of keysyms per keycode 7 is greater
  03/02/2014 18:39:03   than 4 and 51 keysyms are mapped above 4.
  03/02/2014 18:39:03   Automatically switching to -xkb mode.
  03/02/2014 18:39:03   If this makes the key mapping worse you can
  03/02/2014 18:39:03   disable it with the "-noxkb" option.
  03/02/2014 18:39:03   Also, remember "-remap DEAD" for accenting characters.
  03/02/2014 18:39:03 
  03/02/2014 18:39:03 X FBPM extension not supported.
  03/02/2014 18:39:03 X display is capable of DPMS.
  03/02/2014 18:39:03 --------------------------------------------------------
  03/02/2014 18:39:03 
  03/02/2014 18:39:03 Default visual ID: 0x21
  03/02/2014 18:39:04 Read initial data from X display into framebuffer.
  03/02/2014 18:39:04 initialize_screen: fb_depth/fb_bpp/fb_Bpl 16/16/2272
  03/02/2014 18:39:04 
  03/02/2014 18:39:04 X display :0 is 16bpp depth=16 true color
  03/02/2014 18:39:04 
  03/02/2014 18:39:04 Autoprobing TCP port 
  03/02/2014 18:39:04 Autoprobing selected TCP port 5900
  03/02/2014 18:39:04 Autoprobing TCP6 port 
  03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:04 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:05 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:05 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:05 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:05 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:05 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:05 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:05 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:05 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:05 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:05 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:05 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:05 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:05 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:05 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:05 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:05 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:05 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:05 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:05 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:05 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:05 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:05 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:05 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:05 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:05 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:05 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:05 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:05 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:05 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:05 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:05 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:05 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:05 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:05 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:05 rfbListenOnTCP6Port: error in bind IPv6 socket: Address family not supported by protocol
  03/02/2014 18:39:05 Failure autoprobing: Address family not supported by protocol
  03/02/2014 18:39:05 listen6: socket: Address family not supported by protocol
  03/02/2014 18:39:05 (Ignore the above error if this system is IPv4-only.)
  03/02/2014 18:39:05 Not listening on IPv6 interface.
  03/02/2014 18:39:05 
  03/02/2014 18:39:05 Xinerama is present and active (e.g. multi-head).
  03/02/2014 18:39:05 Xinerama: number of sub-screens: 1
  03/02/2014 18:39:05 Xinerama: no blackouts needed (only one sub-screen)
  03/02/2014 18:39:05 
  03/02/2014 18:39:05 fb read rate: 362 MB/sec
  03/02/2014 18:39:05 fast read: reset -wait  ms to: 10
  03/02/2014 18:39:05 fast read: reset -defer ms to: 10
  03/02/2014 18:39:05 The X server says there are 10 mouse buttons.
  03/02/2014 18:39:05 screen setup finished.
  03/02/2014 18:39:05 
  
  The VNC desktop is:      raspberrypi:0
  PORT=5900
  
  ******************************************************************************
  Have you tried the x11vnc '-ncache' VNC client-side pixel caching feature yet?
  
  The scheme stores pixel data offscreen on the VNC viewer side for faster
  retrieval.  It should work with any VNC viewer.  Try it by running:
  
      x11vnc -ncache 10 ...
  
  One can also add -ncache_cr for smooth 'copyrect' window motion.
  More info: http://www.karlrunge.com/x11vnc/faq.html#faq-client-caching
  </code></pre>