bug: Failed to open a design file

Hi ​@Ting Yao, thanks for reaching out! 
 

I completely understand how frustrating it must be to see this toast notification repeatedly pop up. This typically occurs when there’s a network proxy or other network security app blocking some level of access. To clear this issue, please try the following: 

1. Clear the Figma Cache

• If corrupted data is causing the error, clearing the cache often fixes it. 
  • Desktop App (macOS): Go to Help > Troubleshooting and click Clear cache, or quit the app and run rm -rf "$HOME/Library/Application Support/Figma" in the Terminal.
  • Desktop App (Windows): Open the Help menu under the top toolbar (arrow on the right) and select Troubleshooting > Clear cache, or close the app, open %APPDATA%\Figma, and delete the Desktop and DesktopProfile folders.
  • Web Browser: Clear your browser's cookies and cache, then log back in. 

2. Check Your Network & Firewall

• The error can be triggered if your firewall, VPN, or network proxy is blocking Figma's connection. 
  • Try switching to a different network (like a mobile hotspot).
  • Ensure that port 443 is unblocked and that your IT team has whitelisted figma.com. 

3. Test Browser & Account Settings

• Try opening the file in an incognito or private window.
• Test a different supported browser (e.g., Google Chrome, Firefox) to rule out browser-specific extension conflicts.
• Check that you are properly logged in and that you have can edit permissions on the file

For future reference, these troubleshooting steps are also listed in the articles here: Technical troubleshooting tips, Figma browser requirements and Configure your browser for Figma. 
If these don’t help, please try restarting the app or browser app, work in an alternate supported browser (Chrome, Firefox, Safari, Edge), restart your computer and router or modem and check if this clears the issue. Hope this helps!