Hi, I was poking around with the arcsynthesis GL tutorials and wanted to try coding them up in Lisp with SDL2. I was able to get the first tutorial running on Linux, but when I try to run it on Windows, I get an error when calling gl:create-shader. Specifically, SLIME breaks into: NIL is not of type (OR SYMBOL FUNCTION), and can't be FUNCALLed or APPLYed [Condition of type TYPE-ERROR] Is there something special that needs to be done for loading extensions on Windows? The shader-vao sample runs for me, but I can't determine if GLUT is doing something special or not. I can't wholly rule out that I've done something silly, so I've attached the source. -Mick