After a further reboot FAT filesystems can now be mounted, which is strange. I found a side note about that somewhere. I did reboot after installing the new kernel.
Jan 22 2022, David Rosenstrauch via arch-general has written:
On 1/22/22 5:30 AM, Jeanette C. via arch-general wrote:
Hey hey, I just updated my system yesterday and now I can't mount a VFAT filesystem.
Installed packages: linux 5.16.2.arch1-1 util-linux 2.37.2-5
There is no mount.vfat or mount.fat program/script and apparently no kernel module installed that contains "fat" in its name.
Is there a change in the way to mount such filesystems?
Best wishes and thanks for any hints,
Maybe try installing dosfstools?