HELP! No response received from web browser -Creating a Grid

I got this message when I was trying about grid lesson No response received from web browser
I did cash clear, log in again but nothing change at all…
How can I fix it this?
https://gyazo.com/7aa1cfdccafabc0f6fa8ce8274818c48

Please let me know

I believe this is an unfortunate bug that some users experience. Please submit a bug report. I think one way students get around it is by using the “show solution” button.

Thank you !! It’s available now!