You can mount linux ext4 drives on Freebsd using fusefs-ext2 package
# pkg install fusefs-ext2
Enable the fuse kernel module
To enable loading FUSE kernel module at boot add
fuse_load=YES line to the /boot/loader.conf file
# vi /boot/loader.conf...
OK I'm tracking CURRENT, where I have this issue. But I don't think it has anything to do with the fact that it's CURRENT. As writing the headers/tables on an 11 box, results in the same error after rebooting with the drive in the CURRENT box.
Only occurs on USB connected drives --...