A 520 error is a Cloudflare-specific error code for:
"Something is wrong."
Error 520 occurs when the origin server returns an empty, unknown, or unexpected response to Cloudflare.
Contact your hosting provider or site administrator and request a review of your origin web server error logs for crashes and to check for these common causes:
If 520 errors continue after contacting your hosting provider or site administrator, a web developer should provide the following information to Cloudflare Support: