Introduction: The Only Way to Fix a Arduino Uno R3, Arduino Nano Clone.
I accidentally stumbled on this discovery!
Step 1: Fix It!
1. Open preferences in Arduino IDE
2. Open the "additional boards manager urls".
3. Paste this in to it: https://mcudude.github.io/MiniCore/package_MCUdud...
4. Restart Arduino IDE.
5. Click the tab called tools.
6. Click boards manager.
7. Search the words "minicore".
8. Install it.
9. Select atmega328 under the minicore category in the boards menu.
It is fixed!
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