Changing theme name

I’m having an issue with theme name change.
After changing a theme folder name and accordingly changing that name in css the website stops working – shows blank.
What can be the issue?

See the wordpress codex on how to do this.

You are correct, however, that changing the folder, and changing the style.css file will work. I’ve done it for several sites running the theme.

Won’t work when using child theme, unless you fix that also.

If your wp-config.php file has hard coded link to /themename/ – that would need to be changed (not common).

All your caching on the server needs to be cleared completely likely twice.

It does work 🙂