1. Error description

DevTools failed to load SourceMap: Could not load content for 
chrome-extension://ncennffkjdiamlpmcbajkmaiiiddgioo/js/xl-content.js.map: 
HTTP error: status code 404, net::ERR_UNKNOWN_URL_SCHEME
Unchecked runtime.lastError: The message port closed before a response was received.

2. Cause analysis

It is mainly caused by the use of plug-ins such as oil monkey or Xunlei in Google browser

3. Solutions

Address bar entry chrome://extensions/ , turn off the oil monkey or thunder one by one, if not, F12 – & gt; Settings – & gt; Perferences–> Sources, disable JavaScript maps and CSS maps, clear cache and re access