How to Fix a 502 Bad Gateway:
The 502 Bad Gateway error is usually unrelated to your computer or internet connection.
However, since it is possible that there is something wrong on your end, there are some fixes to try.
One popular solution to reloading the URL by tapping F5 or Ctrl+R (Command+R on a Mac), or selecting the refresh/reload.
Although the 502 Bad Gateway error usually indicates a networking error outside of your control, it could be extremely temporary.
As a result, trying the page again is often successful.
source: express.co.uk