VeraCrypt after Sierra upgrade: mount_osxfuse: the OSXFUSE file system is not available (255)
The following script from this link fixes the problem:
https://github.com/osxfuse/osxfuse/issues/315

I called this kextclean:




#!/bin/bash

function status() {
    kextstat | grep org.virtualbox.kext &gt; /dev/null 2&gt;&amp;1 ;
    vbox=$((1-$?))
    kextstat | grep com.github.osxfuse &gt; /dev/null 2&gt;&amp;1 ;
    fuse=$((1-$?))
}

status

if [ "$1" == "vbox" ] ; then
    if [ $vbox == 1 ] ; then
    echo "Already vbox"
    else
        sudo kextunload -b com.github.osxfuse.filesystems.osxfuse
        sudo kextutil "/Library/Application Support/VirtualBox/VBoxDrv.kext" -r "/Library/Application Support/VirtualBox"
        sudo kextutil "/Library/Application Support/VirtualBox/VBoxNetAdp.kext" -r "/Library/Application Support/VirtualBox"
        sudo kextutil "/Library/Application Support/VirtualBox/VBoxNetFlt.kext" -r "/Library/Application Support/VirtualBox"
        sudo kextutil "/Library/Application Support/VirtualBox/VBoxUSB.kext" -r "/Library/Application Support/VirtualBox"
    fi
elif [ "$1" == "fuse" ] ; then
    if [ $fuse == 1 ] ; then
    echo "Already fuse"
    else
        sudo kextunload -b org.virtualbox.kext.VBoxUSB -b org.virtualbox.kext.VBoxNetFlt -b org.virtualbox.kext.VBoxNetAdp
        sudo kextunload -b org.virtualbox.kext.VBoxDrv
        sudo kextutil /Library/Filesystems/osxfuse.fs/Contents/Extensions/10.12/osxfuse.kext
    fi
elif [ "$1" == "status" ] ; then
    echo "vbox = $vbox"
    echo "fuse = $fuse"
else
    echo "Run $0 &lt;vbox|fuse|status&gt;"
fi