Give the following a try:
- Shut down your MacBook Pro completely. Hold the power button until the screen goes black.
- Enter Recovery Mode. Press and hold the Power button until you see Options on screen, then select Options → Continue.
- When the Recovery window appears, try using your external USB-C keyboard or built-in keyboard.
- From Recovery, restart your Mac in Safe Mode: Hold the Shift key (on your external keyboard, if it responds) until you see the login screen. Safe Mode sometimes allows drivers to reload properly.
- If neither keyboard works in Recovery or Safe Mode:
- Try connecting a Bluetooth keyboard (even temporarily) so you can log in.
- Once logged in, open System Settings → General → Software Update and check for any patches Apple may have released for macOS 26.
- If nothing works, you can choose Reinstall macOS from Recovery. This will reinstall the OS without erasing your data.
Finally, if none of the above helps, I suggest that you contact Apple Support directly for further assistance with this issue. To do so, simply select the "Support" link on the lower left-hand side of this forum's web page.
