Arduino Web Editor doesn't work due to an error "avrdude: butterfly_recv()..."

Development Tools Cloud Editor
1

My student uses Arduino Web Editor but it doesn't work due to the following error:

avrdude: butterfly_recv(): programmer is not responding

Let me know any key points to be useful to solve it.

3

She uses Google Chrome 83.0.4103.116 (Official build) (64bit) on macOS 10.15.5.

She tries to run the blink sample, but it cannot be run on Arduino due to the error attached.

エラーメッセージのログ.rtfd.zip (3.98 KB)

4

I gave you links so you would know how to post code and error messages etc.

Please use them so nobody has to download an unknown zip file !

5

I can't post the error log due to:

The message has the following error or errors that must be corrected before continuing:
The message exceeds the maximum allowed length (9000 characters).

6

Then attach it as a TXT file please.

when you next post click "preview" and then you can see the ATTACHMENT option.