Technically, this isn't a "fix" so much as a replacement. The GOG.com version of SWAT 4: Gold Edition is completely DRM-free. It has no disc check at all.
at the bottom to block a defunct ad server that causes issues for the game. Are you using a physical CD downloaded version of the game? CrossOver Support - Community Forums - CodeWeavers Swat 4 No Disc Inserted 20
By default, SWAT 4 supports a limited range of resolutions, typically capping out at the 4:3 standard of the mid-2000s (such as 1600x1200). Modern monitors use 16:9 or 16:10 aspect ratios (e.g., 1920x1080). If you force the game to run on a modern screen without patching it, you might see a "No Disc" error after changing resolution settings, or simply a black screen because the game cannot validate the display mode. Technically, this isn't a "fix" so much as a replacement