NFS server on the host or a flash command has failed

Question: During flashing, I get a “Flash failure” error mentioning an NFS server issue. How can I resolve it?

This error may occur during Jetson Orin NX or Orin Nano flashing if the NFS server on the host is not functioning properly. The terminal output typically shows:

Flash failure
Either the device cannot mount the NFS server on the host or a flash command has failed...

This issue often appears after the device reboots mid-flash and reconnects (seen as 0955:7035 in lsusb). At that point, the host tries to SSH into the device, and if the NFS server isn’t working, the process fails.
Reinstall the NFS server package on the host machine:
$ sudo apt install --reinstall nfs-kernel-server

Then restart the flashing process.