See http://www.clausbrod.de/OneSpaceModeling/OsdmFaqTroubleshooting#SignalReceived for background on the message. This is a generic error message which is displayed when there isn't much other information for the user. In some cases, you can find out more by entering the following command in the user input line: (display (f2::get-last-exception)) This will open the display box window and display some internal crash information. Copy the data from the window, paste it into a text file, and post the text file here. This will hopefully lead us into the right direction. From your description, it sounds like you get the crash whenever you try to open the file dialog, either for saving or loading. If so, the culprit might be a system component which installs itself as a Windows shell extension. (Those shell extensions are loaded into a process whenever the process opens a file dialog.) Claus