opening PgAdmin 4 in Chrome

There is a strange behavior with the new version 4.28 that is addressed in the FAQ:

When I launch pgAdmin 4 v4.28 or later on Windows, the loading page never closes. Why?

pgAdmin 4 v4.28 includes additional security features, one of which is intended to prevent security issues caused by Content Sniffing.

Unfortunately some Windows systems are mis-configured such that this causes Javascripts used by pgAdmin to fail to load. Opening the developer tools on your browser will show an error similar to this:

Refused to execute script from 'http://127.0.0.1:57313/static/vendor/require/require.min.js?ver=42800' because its MIME type ('text/plain') is not executable, and strict MIME type checking is enabled.

(index):39 Uncaught ReferenceError: require is not defined at (index):39

This will occur when the value of the registry key at HKEY_CLASSES_ROOT\.js\Content Type is set to text/plain. To resolve the issue, use the Registry Editor and reset the value of HKEY_CLASSES_ROOT\.js\Content Type to:

text/javascript

Finally, restart the pgAdmin server.