Hi Suruchigoel, This can be happening for a variaty of reasons that has to do mostly with the OS and/or the video card drivers: 1- If you are using the Unity desktop manager, can you change to something more standard like KDE? 2- Are you connect to the Ubuntu from a Windows machine? If so, try not using Xming, but instead try Reflection X or Cygwin. 3- Try using Software rendering mode instead. For example, from the Linux prompt you can start IDL like this: idlde -IDL_GR_X_RENDERER 1 or idl -IDL_GR_X_RENDERER 1 Or you can change this from inside IDL Workbench, by going to the Preferences -> IDL-> Graphics 4- The video card and/or the video driver version used: try updating the video card drivers if you can. 5- Another workaround for some users was to rename the IDL gl_drivers.so files: cd /usr/local/itt/idl81/bin/bin.linux.x86 mv gl_driver.so gl_driver_donotuse.so cd /usr/local/itt/idl81/bin/bin.linux.x86_64 mv gl_driver.so gl_driver_donotuse.so After doing that the problem should go away. Cheers, Fernando