If you are on Mac and see a blank login window when you try to start the Minecraft Launcher, follow these steps:
Check your Mac for updates
- Select the Apple logo in the top left corner.
- Select System Settings.
- Select General.
- Select Software update.
- Install any available updates.
Clear Safari Cookies
- Open Safari.
- Select Safari in the menu bar.
- Select Settings.
- On the Privacy tab, select Manage Website Data.
- Select Remove all.
- Confirm by selecting Remove Now.
- Relaunch Safari.
Clear Safari Cache
- Open Safari.
- Select Safari in the menu bar.
- Select the Advanced tab.
- Make sure Show features for web developers is selected and Block all cookies is not selected.
- Close the window and restart Safari.
- Select Developer in the menu bar.
- Select Empty Caches.