Is this happening for all your files or just a particular file? Is the file loading ok in the browser? What troubleshooting steps have you tried so far?
logging out and back in
clearing your browser/desktop app cache
un-installing and re-installing the desktop app
Here’s how to clear the desktop app cache on Windows:
Close the Figma desktop app
Open the Start menu, and paste in this, followed by enter: %APPDATA%\Figma
In the window that opens, delete the Desktop and DesktopProfile folders if they exist