How can I remove this link warning? You can see code segment that causes this warning.
static AFX_EXTENSION_MODULE GuiCtrlsDLL = { NULL, NULL };
//bla bla
//         
        
In addition to reading the warning message, pay attention to where it occurs if you have multiple projects as part of a workspace.
I wasted time looking for a problem in my DLL which was compiling and linking correctly. The workspace was also building the main application and my error was that I had inadvertently included a new (DLL) source file into the build file list of the application itself.
The main program requires the DLL header mynewdll.h to import things but does not require the source file mynewdll.cpp. (The code is brought in at run time with a DLL.) I have a habit of including header and code files into projects as a pair, and this is where I had gone wrong.
I would have detected the error much sooner if I had been alert and noticed that the DLL project linked with no errors and it was the main program that complained!
My DLL source code and project was error free and it was only the way I tried to build my executable that was faulty.