chrome suddenly can't access github

1. Background:

Previously, github could always be accessed normally. Suddenly one day I can't access github anymore, and I can't even hang up a ladder.

Two, the solution

Type in your browser:

chrome://net-internals/

After entering, click Proxy on the left, and then click Re-apply settings and Clear bad proxies inside

Then click DNS on the left and click Clear host cache on the right of Host resolver cache