Wish I'd seen this a few months ago. Was upgrading from V22 to V30 all went well then my security certs expired, by coincidence, the day after the upgrade. Replacing the certs according to the information that I had resulted in errors (can't recall what they were but basically the entire system was unusable). Had to do a complete re-install of a vanilla system and then upgrade/import the changed bits in a very hasty rush to recover the situation as I couldn't just restore the previous version because the certs were going to expire independent of the upgrade. Your solution would have saved me so much heartache.