After nearly a year permanently operation its now time. The DW20 1.12 will be retired to make space for a new pack.
Also the last two upgrade attempts, to bring the server up to date (pack version 2.3.0), failed because all the previous upgrades form 1.5.0 (the version with which we started the server) to 2.1.0 (on which the server right now) slowly corrupted the world (all this mods which where over time added or removed and left data in the world files).