Comment 2 for bug 1492464

The error in the logs is:

Setting up cryptsetup (2:1.6.6-5ubuntu2) ...
update-initramfs is disabled since running on read-only media
update-rc.d: warning: start and stop actions are no longer supported; falling back to defaults
insserv: Service checkroot has to be enabled to start service cryptdisks-early
insserv: exiting now!
update-rc.d: error: insserv rejected the script header
dpkg: error processing package cryptsetup (--configure):
 subprocess installed post-installation script returned error exit status 1

Why is checkroot not enabled on your system? Please show the output of:

 ls -l /etc/rcS.d/*checkroot.sh