How to fix this Bootcamp problem?

This is for a Windows 10 ISO, right? Try going to Action > Download Windows Support Software instead.

You can first update your macOS system, ensure a stable network connection, and then restart Boot Camp Assistant to attempt the installation.

Of course. "Boot Camp problems" can cover a lot of ground, but based on the context of your previous question about the Windows 11 upgrade failure, we can focus on the most likely culprits and their solutions.