I compile an application of mine cross platform. It runs Win32, Win64, OSX, Linux. For me the qcustomplot control works fine across all platforms. I have a user who is trying to use the program on OSX but running into trouble. When he tries to bring up the qcustomplot widget it appears but with everything double sized. That is, in the place where the qcustomplot is supposed to be drawn you see only the upper left quarter of the actual control. It's double sized in other words and you thus only can actually see a quarter of it drawn large. Also, my mouse based interactions don't seem to work. The only thing I can think of is that this is some sort of OpenGL error as I do have opengl turned on. Is that a possible reason? Are there any other reasons for this to happen?