New error- just started happening

Do this:

  1. Select File > Preferences from the Arduino IDE menus.
  2. Check the box next to "Show verbose output during: [] compilation.
  3. Click the OK button.
  4. Select the board you are interested in from the Arduino IDE's Tools > Board menu.
  5. Compile any sketch.
  6. Wait for the compilation to finish.
    (it should be OK even if it fails)
  7. Scroll up the black console pane at the bottom of the Arduino IDE window all the way to the top.

You should see a line that looks something like this in the output:

Using board 'generic' from platform in folder: C:\Users\<user name>\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\3.0.2

That is the location.