<didn't install Oolite from the installer in a while, mostly compiling and running it from the source, but, still ... />
After installing you should have 2 options (IIRC):
1. If you installed is as a root, for all users, running oolite (not .oolite -- note the missing point) in Terminal, should do. Otherwise the whole path to the executable should be something like: /usr/lib/GNUstep/Applications/Oolite/oolite (or /usr/lib64/[...], if your Linux is x86_64)
2. If you installed it only for your user, then the command line to start it in terminal should be:
I installed Oolite into my own user directory because this computer has only one user (me) and isn't a part of any network so I didn't see any benifit to installing it to the root directory.
But because you try to start it from the Games menu in Xfce, and it doesn't work, you can try to open the ~/.Oolite/Logs/Latest.log file, with a text editor, and see if there are any issues reported there (maybe post the contents here and someone would give you some hints).
I looked at the Latest.log but I'm afraid it doesn't make any sense to me.
Here is a copy of my Latest.log for your review:
Opening log for Oolite version 1.80 (x86-64) under Linux 3.13.0-24-generic at 2014-12-24 17:41:22 -0600.
1 processor detected.
Build options: OpenAL, new planets.
Note that the contents of the log file can be adjusted by editing logcontrol.plist.
17:41:25.121 [oxp.conflict]: OXP oolite.oxp.Lone_Wolf.ShieldCyclerNext.oxz conflicts with oolite.oxp.Lone_Wolf.ShieldCycler.oxz and was removed from the loading list
17:41:25.127 [dataCache.rebuild.pathsChanged]: Cache is stale (search paths have changed). Rebuilding from scratch.
17:41:26.290 [display.mode.list.native]: X11 native resolution detected: 1366 x 768
Closing log at 2014-12-24 17:41:26 -0600.
notice that there appear to be OXP conflicts listed in the Latest.log.....this has to have something to do with the vanilla install of Oolite because I haven't installed any addon's at this point.
Thank you for your help Commander_X.
It is greatly appreciated.