The editor freezes when adding a scene, the preview stutters, or your project shows a loading error? Work through this checklist from top to bottom; in most cases that solves it.
The checklist
Reload the page: Reload the editor with cmd+R (Mac) or Ctrl+R (Windows). Your changes are saved.
Update your browser: Use the current version of Chrome or Edge. An outdated browser is the most common cause of freezes.
Close tabs and programs: Video editing in the browser needs memory. Close tabs and programs you do not need.
Clear the cache: Clear your browser cache for app.cofenster.com and sign in again.
Try another network: VPNs and restrictive company networks can block video loading. Test on a hotspot, for example. The domains your IT needs to allow are listed in the cofenster domains article.
Try another browser: Does it work in a fresh Chrome profile or a different browser?
If nothing helps
Message us in the chat and include: the project name or link, what exactly happens (for example "freezes when adding a scene"), your browser, and whether the problem persists after the checklist. That way we can look into the project right away instead of asking back.