Hi, I checked the development build on my old Macbook Pro with High Sierra 10.13.6 and the newer one with Catalina 10.15.7. I tried running the compiled binary and then rebuilding with setup_macosx.command. On High Sierra recompilation was necessary, because the qb64 binary didn't work out of the box, as it was apparently built on a later system. In both cases recompilation went smoothly and after that qb64 launched just fine. Anyway, in all cases I tested with the development build, on both Macbooks, the screen now looks correct. Thanks!