How to debug CSS optimization warnings
CSS optimization errors are very rare. They are usually caused by custom code components using private Framer APIs. In rare cases they might indicate a bug in Framer.
In Aug-Sep 2025, Framer has released a new CSS optimizer. This optimizer isn’t compatible with some older versions of some components, such as Vimeo and Code Block from Framer. All current Framer components are compatible with the new CSS optimizer.
If you see the error below:
Check if there’s an update available for components, and update them.
Reach out to Framer Support if all components are up-to-date, and the issue still persists