Starting a VM, I get an error in log:
mount: unknown filesystem type 'crypt_LUKS'
All OnApp versions
Boot in recovery mode and try to convert the filesystem back to the appropriate type (usually ext3) or use other tools to try and salvage data.
The disk simply won't be bootable in OnApp as-is, and it may be needed to restore from a backup or rebuild the VM, as OnApp does not support encrypted volumes.