I downloaded the "Ubuntu 16.04 / 64-bit tar.gz" code and installed it. I got an error.

jw@logopolis:~$ uname -a
Linux logopolis 4.4.0-36-generic #55-Ubuntu SMP Thu Aug 11 18:01:55 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux

jw@logopolis:~$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 16.04.1 LTS
Release: 16.04
Codename: xenial

jw@logopolis:~$ prince
/usr/local/lib/prince/bin/prince: error while loading shared libraries: libcurl.so.4: cannot open shared object file: No such file or directory

So you seem to be linking to an older version of libcurl, if I understand correctly.

I ended up using the generic linux version and it was fine. Just thought you should know this isn't working quite right.

What libraries do you see if you run "dpkg --list | grep curl" ?

ii curl 7.47.0-1ubuntu2.1 amd64 command line tool for transferring data with URL syntax
ii libcurl3-gnutls:amd64 7.47.0-1ubuntu2.1 amd64 easy-to-use client-side URL transfer library (GnuTLS flavour)
ii python3-pycurl 7.43.0-1ubuntu1 amd64 Python bindings to libcurl (Python 3)

Can you install the "libcurl3" package, which is the OpenSSL flavour of libcurl?