Verified for macOS Tahoe 26.2
Fix Guide: Render Artifacts & UI Flickering on macOS Tahoe
Symptom: You see strange visual "glitches," flickering desktop icons, or "transparent boxes" instead of shortcuts. These artifacts often appear on Apple Silicon (M1/M2/M3/M4) Macs after updating to macOS Tahoe.
Why this happens
macOS Tahoe 26.x features a redesigned compositing engine for the UI. On some Apple Silicon models, this engine has a "memory leak" in the GPU frame buffer, which causes the system to fail to render icons or windows correctly, leaving "ghost" artifacts behind.
Fix 1: Restart the Window Server (Free)
This "soft reset" clears the GPU memory without requiring a full computer restart.
**Open Activity Monitor**
- Go to Applications > Utilities > Activity Monitor.
**Find WindowServer**
- Search for `WindowServer`.
**Force Quit**
- Click the **X** button and select **Force Quit**.
- *Note: Your screen will go black for a second and you will be logged out. Save your work first.*
Fix 2: The "Reduce Transparency" Workaround (Free)
If the artifacts return, reducing the GPU load on the UI can stop the flickering.
**Open System Settings**
- Go to **Accessibility > Display**.
**Enable Reduce Transparency**
- Toggle **Reduce transparency** to ON.
- This removes the "blur" effect from windows, which is often what triggers the rendering glitch.
Fix 3: The Professional Stability Path
When UI glitches are caused by driver conflicts or low video memory.
If your Mac is constantly "flickering," it may be struggling with outdated caches or background processes that are competing for the GPU's attention.
Recommended Tool: CleanMyMac X
- **Maintenance Module:** The "Repair Disk Permissions" and "Speed Up Mail" modules help clear the system databases that the UI relies on to pull icon data.
- **Uninstaller:** If a specific app (like an old Photoshop version) is causing the flicker, CleanMyMac X ensures a "clean" removal of the buggy display drivers that might be left behind.
[Link: Clean Your System Graphics with CleanMyMac X]
Performance Monitor: iStat Menus
iStat Menus can show you the "GPU Memory" usage in your menu bar. If you see it hitting 90%+, you know it's time to quit high-load apps before the artifacts start.
[Link: Monitor GPU Health with iStat Menus]