i have tried that, in the shell, they start and then exit, no error messages, however if you add a --help it runs and gives you the options. just graphically starts and exits, nothing on the xwindows display.
When a program won't start for me it's most often after I've updated another that did something to a dependency of said program. Trying to start it from the terminal usually shows it to be an .so file and reinstalling said program usually does the trick.
very odd, just compiled Thunderbird with gtk3 and it exits without showing anything on the xwindows display, i recompiled with gtk2 and it works perfectly, maybe all my trouble with apps quiting is if they are compiled against gtk3
I wrote yesterday in the gtk3/firefox thread.
I don't know if this is the real cause of your problem,
but maybe it is the x11-theme.
The post from yesterday:
Look at this thread: https://forums.freebsd.org/threads/60498/#post-347876
I have installed x11-themes/gtk-arc-themes and use the settings.ini which posted someone in this thread (and this solved the problem - in this thread it was my problem).