ESP32 board installation error for CRC mismatch

Add the link to arduino IDE>Files>Preferences>Additional Board Manager URLs:

Open Board Manager and search for ESP32.

Just edit the file C:\Users\Admin\AppData\Local\Arduino15\package_esp32_index.json in notepad++ or any supporting editor.

Delete the checksum details inside " " according to the version like 1.0.4 or else.

Save it and open board manager of arduino.

Now download the esp32 board manager file…

Save it and open board manager of arduino.

When you do that, it just downloads a fresh copy of and overwrites your modified version at C:\Users\Admin\AppData\Local\Arduino15\package_esp32_index.json, so your edit accomplishes nothing. I suspect it is pure coincidence that the problem went away after you edited package_esp32_index.json.