This has been a common problem on forums but solutions elude me. Windows 10 64 bit, CGAL 4.11, Cmake 3.9.2, Boost 1.65.1, Qt5 for MSVS 2017, libQGLViewer 2.7.0, Visual Studio 2017, CGAL built both as Debug and Release, myriad C++ include paths and Windows user path variables tried. Same thing that it can't open, not necessarily can't find, a main CGAL library file. The .lib file certainly exists. When I try to run a simple CGAL test program, I can't get past this error.