Could not mount boot fs

I’m trying to reinstall kodi 18 from kodi 19. Have got a boot disk but keep getting the error message “install failed could not mount boot fs”. I trying to use the following disk image 2021.08-1. as I think this is the one before the update. Can anyone advise?
Have tried a different sd card and a different image (2020-11-1) same thing.
Have also tried installing a backup from last year no luck.
Also found a thread that suggested using “sudo apt-get install --reinstall vero3-mediacenter-osmc=18.6.0-13” but get error message not found.

Use a newer image or the other USB port.

Thanks very much Sam, the other port solved it.
Is 2020-10-1 the last one before kodi 19?

2020.11-1 should be.