I'm running Ubuntu 16.04. I get this message:

WARNING: Failed to download libnpsol.a from https://openmx.ssri.psu.edu/packages/npsol/linux/x86_64/gcc5.4/libnpsol.a
** libs

Here are the details:

rick@rick-CT14:~$ sudo R

R version 3.3.1 (2016-06-21) -- "Bug in Your Hair"
Copyright (C) 2016 The R Foundation for Statistical Computing
Platform: x86_64-pc-linux-gnu (64-bit)

R is free software and comes with ABSOLUTELY NO WARRANTY.
You are welcome to redistribute it under certain conditions.
Type 'license()' or 'licence()' for distribution details.

Natural language support but running in an English locale

R is a collaborative project with many contributors.
Type 'contributors()' for more information and
'citation()' on how to cite R or R packages in publications.

Type 'demo()' for some demos, 'help()' for on-line help, or
'help.start()' for an HTML browser interface to help.
Type 'q()' to quit R.

[Previously saved workspace restored]

> source('https://openmx.ssri.psu.edu/getOpenMx.R')
You are now installing the latest version of OpenMx.Installing package into ‘/home/rick/R/x86_64-pc-linux-gnu-library/3.3’
(as ‘lib’ is unspecified)
trying URL 'https://openmx.ssri.psu.edu/OpenMx2/src/contrib/OpenMx_2.6.9.tar.gz'

Content type 'application/x-gzip' length 4612150 bytes (4.4 MB)

downloaded 4.4 MB

• installing source package ‘OpenMx’ ...
  Change default C/C++ compiler and default compile flags by editing ~/.R/Makevars
  WARNING: Failed to download libnpsol.a from https://openmx.ssri.psu.edu/packages/npsol/linux/x86_64/gcc5.4/libnpsol.a
  ** libs
  g++ -std=c++11 -I/usr/share/R/include -DNDEBUG -I"/home/rick/R/x86_64-pc-linux-gnu-library/3.3/Rcpp/include" -I"/home/rick/R/x86_64-pc-linux-gnu-library/3.3/RcppEigen/include" -I"/home/rick/R/x86_64-pc-linux-gnu-library/3.3/StanHeaders/include" -I"/home/rick/R/x86_64-pc-linux-gnu-library/3.3/BH/include" -I"/home/rick/R/x86_64-pc-linux-gnu-library/3.3/rpf/include" -fopenmp -Wall -Wextra -Wno-unknown-pragmas -Wno-unused-parameter -Wvla -Wno-unused-local-typedefs -fdiagnostics-color=auto -fpic -g -O2 -fstack-protector-strong -Wformat -Werror=format-security -Wdate-time -D_FORTIFY_SOURCE=2 -g -c Compute.cpp -o Compute.o
  In file included from /home/rick/R/x86_64-pc-linux-gnu-library/3.3/RcppEigen/include/Eigen/Core:276:0,
  from omxMatrix.h:38,
  from omxState.h:52,
  from glue.h:23,
  from Compute.cpp:23:
  /home/rick/R/x86_64-pc-linux-gnu-library/3.3/RcppEigen/include/Eigen/src/Core/Functors.h:973:28: warning: ‘template class std::binder2nd’ is deprecated [-Wdeprecated-declarations]
  struct functor_traits >
  ^
  In file included from /usr/include/c++/5/bits/stl_function.h:1128:0,
  from /usr/include/c++/5/string:48,
  from /usr/include/c++/5/random:40,
  from /usr/include/c++/5/bits/stl_algo.h:66,
  from /usr/include/c++/5/algorithm:62,
  from Compute.cpp:17:
  /usr/include/c++/5/backward/binders.h:143:11: note: declared here
  class binder2nd
  ^
  In file included from /home/rick/R/x86_64-pc-linux-gnu-library/3.3/RcppEigen/include/Eigen/Core:276:0,
  from omxMatrix.h:38,
  from omxState.h:52,
  from glue.h:23,
  from Compute.cpp:23:
  /home/rick/R/x86_64-pc-linux-gnu-library/3.3/RcppEigen/include/Eigen/src/Core/Functors.h:977:28: warning: ‘template class std::binder1st’ is deprecated [-Wdeprecated-declarations]
  struct functor_traits >
  ^
  In file included from /usr/include/c++/5/bits/stl_function.h:1128:0,
  from /usr/include/c++/5/string:48,
  from /usr/include/c++/5/random:40,
  from /usr/include/c++/5/bits/stl_algo.h:66,
  from /usr/include/c++/5/algorithm:62,
  from Compute.cpp:17:
  /usr/include/c++/5/backward/binders.h:108:11: note: declared here
  class binder1st