Added by Parth Maheshwari (พาร์ท) 6 months ago
The reason behind this error is that some ESP32 boards don't go into flash/download mode automatically when you try to deploy new code to them. If you are facing this error, your board may be one of them.
There is a simple solution (but you will have to do this every time you want to deploy code to this ESP32 board of yours), and there is a permanent solution.
Simple solution: As soon as you see the message "Waijung 2: Downloading to the target" (you will see this message towards the end of the build process as this is the last step), please hold down on the BOOT/FLASH button on your ESP32 until the build procedure is complete . This will restart the chip and put it into download mode and fix the problem.
Permanent solution - you can try soldering a 10 uF electrolytic capacitor between the EN and GND pins of your ESP32.