Compiling/Linking with -no-opengl on Windows and in 6.5.3 an "identifier not found" message is generated for the getAdapterLuid() method. It appears there in an imbalance in the conditional compile directives in web_engine_context.cpp. The definition of the method is conditional on opengl AND Q_OS_WIN whereas the reference/call to the method is only conditional on the Q_OS_WIN.