The Platform.txt file is at: C:\Users\<your user name>\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\2.5.2 Note: <your user name> is the name you log in under (assuming windows). You can see it by looking at C:\users\ The folder "AppData" is hidden from normal view. You will have to change the "File Explorer" settings to be able to see it.
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