Finally my program (mainSimple.cpp) works!!! I added to my project these libraries: Gmsh.lib fltk.lib fltkgl.lib fltkforms.lib fltkimages.lib fltkjpeg.lib fltkpng.lib fltkz.lib med.lib hdf5.lib blas.lib lapack.lib g2c.lib gcc.lib opengl32.lib glu32.lib wsock32.lib comctl32.lib Cheers Mikhail Artemiev, happy PhD student, NSTU