Hello guys. I have exactly the same problem when updating from 1.16.3 zu 1.17.2
After some testing I setup both versions on the same server in two different apache vhosts.
Both are using exactly the same database aod ost-config-file, so there is no database key setting the system to offline.
as mentioned they use exactly the same database in the ost-config.php
(I tried it with 1.17.0 and 1.17.1 before.. same behaviour)
Anyone an idea? Thank you 🙂