I could not start the program from terminal, this is why I took help from linux forums. It suggested I open the TmoleX19.desktop file by gio-open, gtk-launch, xdg-open, gvfs open etc which also failed.
In my /home/mslab/COSMOlogic/TmoleX19 this .desktop file remains. However, inside that directory, there also remains a directory Tmolex inside which a TmoleX19 file (POSIZ shell script) remains which can be opened by sh command.
Upon suggestion from ubuntu forums, I changed the file content of .desktop as,
Exec="/home/mslab/COSMOlogic/TmoleX19/TmoleX/TmoleX19"
to
Exec=env LIBGL_ALWAYS_SOFTWARE=1 MESA_GL_VERSION_OVERRIDE=2.1 "/home/mslab/COSMOlogic/TmoleX19/TmoleX/TmoleX19"
However, same error occurred. Any hint or where I have made a mistake from your expert eyes?