After further analysis on our side, it looks like if you upgraded to Raspbian Stretch AFTER you cut the Lock tabs, then you may not be able to rebuild your system. Stretch is a major release update and there are too many variables - between Stretch and your application space - for us to be 100% sure what is going on in your specific application.
Internal testing results
When we performed an upgrade from Jessie to Stretch on an already encrypted file system, we did experience problems:
- Started with a bare Jessie Lite install
- Installed Zymkey software components
- Converted SD card root file system to LUKS encrypted volume using Zymkey locking on the LUKS key per community post
- Upgraded to Raspbian Stretch
Specifically the initramfs is complaining that it can’t find the necessary drivers due to the kernel version being different in Stretch. This is a kernel issue, not directly related to Zymkey.
RPi community does caution of upgrade issues from Jessie to Stretch. See the Raspberry Pi page which announces Stretch release (https://www.raspberrypi.org/blog/raspbian-stretch/):
Upgrading an existing Jessie image is possible, but is not guaranteed to work in every circumstance. If you wish to try upgrading a Jessie image to Stretch, we strongly recommend taking a backup first – we can accept no responsibility for loss of data from a failed update.
To save you further problems please contact Zymbit support directly, including your community handle, and we will try to take care of you.
In the interim we have added a Warning to the getting started guide to NOT cut the tab until after you have settled on a major code distribution. Also we will recommend Jessie for new apps, until Stretch has settled down. (next 4 to 6 weeks)