Filesystem was not properly dismounted

If you hard reset FreeBSD you may get the following message

/ was not properly dismounted

To resolve this boot into single user mode and run the following command:

fsck -y

Once the filesystem check is complete (and it comes back clean) you can reboot.

Reference

https://wiki.umiacs.umd.edu/VirtualMeshTest/index.php/Fix_the_file_system_error_on_FreeBSD