Hi, I'm running IDL 5.6 on Windows XP. I have discovered the usefulness of LIVE_PLOT in comparison with PLOT and started fooling around with the settings to create personalized plots. In an attempt to delete the plot-windows, I gave the command: >LIVE_DESTROY,/ENVIRONMENT That was obviously a bad idea: ever since, LIVE_PLOT refuses to work, generating the error message: "Error occurred in LIVE_PLOT. Unable to invoke method on NULL object reference: OWINDOW." Nothing seems to help to solve it: resetting IDL, restarting IDL, even reinstalling IDL... Any ideas what has happened and how to fix it? Victor