This error means that the xinit(1) program, which sets up X11 resources and starts a window manager, failed to locate the X server process. Perhaps the user interrupted window system startup, or exited abnormally from OpenWindows (for example, by killing processes or by rebooting). The X server might have crashed. Data loss is possible in some cases. Depending on the process timing, this message might be normal when the OpenWindows environment exits during a system reboot.
The only solution is to exit and restart the OpenWindows environment. You do not need to reboot the system unless it hangs and fails to give you a console prompt. To exit the OpenWindows environment, select Workspace->Exit. To restart the OpenWindows environment, type openwin(1) at the system prompt.