If you can, try rebooting the server.  That message often occurs if the START_UP.RUN license file gets hung open.  Another possibility if that doesn't work, is that the file is damaged.  If that is the case, call DBA and ask them to email you a new file.  Don't ask for tech support because you will have to wait for them to call you back.  Just tell them you need a new START_UP.RUN file emailed to you.