FreeBSD 11.0 Release - swap file - panic when reboot

Hi ))

OS FreeBSD 11.0-RELEASE #0 r306362

I create swapfile use mdconfig tool
File save in the /usr catalog

# cat /etc/fstab
# Device        Mountpoint      FStype  Options Dump    Pass#
md99            none            swap    sw,file=/usr/swap0,late 0 0

I reboot and see the error
panic: swap_pager_force_pagein: read from swap failed

Tell me please.
How fix this ?
I'm not sure but this could happen if the startup scripts try to enable swap before the /usr filesystem is mounted.
If that is the case, you will have to enable swap after the /usr file system is mounted.