After updating a MacBook Pro (M1 Pro) from macOS 15.8 to the 15.8.2 release candidate (24H219), every OpenGL context that is attached to a window has no default framebuffer. NSOpenGLView and -[NSOpenGLContext setView:] are both affected, so anything drawn that way shows a blank window. I filed FB25133383 with a minimal sample, kernel log and call trace. Symptoms kCGLCPHasDrawable is 0, glCheckFramebufferStatus(GL_FRAMEBUFFER) returns GL_FRAMEBUFFER_UNDEFINED (0x8219), and glClear raises GL_INVALID_FRAMEBUFFER_OPERATION (0x506). For every attach attempt the kernel logs: (IOGPUFamily) IOGPUGLDrawableUserClient::set_surface(sIOGPUGLDrawableClientSetSurfaceData *): Invalid surface ID = N CGLSetSurface returns kCGLBadDrawable (10005). Stepping through it, CGSBindSurface succeeds and the IOGPU user-client call then fails with kIOReturnBadArgument. What still works Offscreen FBOs in the same context. CAOpenGLLayer and NSOpenGLLayer render correctly in the same process. Only the window-surface path is broken. Minimal sample (public API only) // clang -fobjc-arc -Wno-deprecated-declarations -framework Cocoa -framework OpenGL repro.m -o repro && ./repro #define GL_SILENCE_DEPRECATION 1 #import <Cocoa/Cocoa.h> #import <OpenGL/OpenGL.h> #import <OpenGL/gl.h> #import <OpenGL/glext.h> @interface ReproView : NSOpenGLView @end @implementation ReproView - (void)drawRect:(NSRect)dirtyRect { NSOpenGLContext *ctx = [self openGLContext]; [ctx makeCurrentContext]; GLint hasDrawable = -1; CGLGetParameter(ctx.CGLContextObj, kCGLCPHasDrawable, &hasDrawable); GLenum status = glCheckFramebufferStatus(GL_FRAMEBUFFER); glClearColor(0, 1, 0, 1); glClear(GL_COLOR_BUFFER_BIT); GLenum err = glGetError(); printf("hasDrawable=%d status=0x%x glError=0x%x\n", hasDrawable, status, err); fflush(stdout); [ctx flushBuffer]; } @end int main(void) { @autoreleasepool { NSApplication *app = [NSApplication sharedApplication]; [app setActivationPolicy:NSApplicationActivationPolicyRegular]; NSWindow *win = [[NSWindow alloc] initWithContentRect:NSMakeRect(200, 300, 240, 240) styleMask:NSWindowStyleMaskTitled | NSWindowStyleMaskClosable backing:NSBackingStoreBuffered defer:NO]; NSOpenGLPixelFormatAttribute attrs[] = { NSOpenGLPFADoubleBuffer, NSOpenGLPFAAccelerated, 0 }; NSOpenGLPixelFormat *pf = [[NSOpenGLPixelFormat alloc] initWithAttributes:attrs]; [win.contentView addSubview:[[ReproView alloc] initWithFrame:NSMakeRect(20, 20, 200, 200) pixelFormat:pf]]; [win makeKeyAndOrderFront:nil]; [app activateIgnoringOtherApps:YES]; dispatch_after(dispatch_time(DISPATCH_TIME_NOW, 5 * NSEC_PER_SEC), dispatch_get_main_queue(), ^{ [app terminate:nil]; }); [app run]; } return 0; } Expected: a green square and hasDrawable=1 status=0x8cd5 glError=0x0. On 24H219: nothing is drawn and it prints hasDrawable=0 status=0x8219 glError=0x506. Scope Same result for arm64 and x86_64 under Rosetta, layer-backed or not, main thread or background thread. Affected on my Mac: Sony Imaging Edge Desktop Viewer (NSOpenGLView), DJI Studio (Qt 6, NSOpenGLContext) and its Quick Look extension. Public reports with the same symptom on 24H219: kitty #10645, Alacritty #9067, Godot #124311, Bambu Studio #12530 (all on GitHub). They cover M1, M4, M4 Pro and M4 Max, and the Alacritty report says 15.8.1 was fine. Questions Is this a known issue in the 15.8.2 RC, and will it be fixed before 15.8.2 ships? Is anyone seeing it on the macOS 26.7.2 RC or the 27.2 beta? Workaround for developers in the meantime: render into an IOSurface-backed FBO and present that surface in a CALayer, or use CAOpenGLLayer.