As this is the process to query extension in glew.c it does not work with an opengl 3 core/forward context. glGetStringi must be used .
Duplicate of Bug 2927731: Calling glGetString(GL_EXTENSION) even in Core/FC context Closing.
Closing as a duplicate.
Duplicate of Bug 2927731: Calling glGetString(GL_EXTENSION) even in Core/FC context
Closing.
Closing as a duplicate.