DevTools failed to load SourceMap: Could not load content for popper.min.js.map on Chrome browser

Issue

• While using a production instance of Liferay, the below warning will appear in the Chrome console:
  

  DevTools failed to load SourceMap: Could not load content for http://localhost:8080/popper.min.js.map: HTTP error: status code 404, net::ERR_HTTP_RESPONSE_CODE_FAILURE

Environment

• Liferay DXP 7.2
• Liferay DXP 7.3
• Liferay DXP 7.4

Resolution

• The warning does not flag any Liferay bugs and can be safely ignored
• As a client-side workaround, customers can navigate to the "Settings" for Developer Tools, then uncheck Enable JavaScript Sourcemaps under the "Sources" settings:
  
• The popper.min.js.map file, per se, allows the debugging of popper.js.
• Debug mode in Liferay is triggered by adding, among others, the below two properties:
  

  javascript.fast.load=false
  minifier.enabled=false

  With these 2 lines, the warning will no longer be printed and debug for Popper.js source map will be possible.
• When in a production environment, normally these properties are set to true, then the source maps are no longer available, as we activate fast load which is using ComboServlet.java to group and load more files at the same time (JS or CSS), so it is more efficient. Because of this, some source maps are not being found and are failing (for example, popper.min.js.map).

Additional Information

• A Feature Request in Jira has been raised to handle this message in future Liferay releases: https://issues.liferay.com/browse/LPS-118828