Hi Rick,
Sorry, my misake in typing here the library name.
Anyway, I get the same error message using 3dSkullStrip - that libgsl.so.0 does not exist. I manually tried to open libgsl.so.0 (in both /usr/lib/ and /usr/lib/x86_64-linux/gnu/), and got a message that the link was broken. I removed the file and re-installed it (using the command lines you suggested on October 15 in this thread). And still the link is broken.
If it helps, running again sudo apt-get install libxp6 python-qt4 r-base libpng16 libgsl0-dev tcsh, I noticed the message "unable to locate package libpng16". Perhaps that's where the crux is?
Thanks,
Galit