Nexus 2 detected and failed startup in most cases where configuration file compatibility versions were conflicting.
Some Nexus 3 users accidentally or intentionally startup old versions of Nexus 3 against newer upgraded versions of Nexus 3 data directories. This may lead to potential problems and is certainly a state which is considered "unknown". This complicates trying to solve any other reported problem with a running instance.
- Nexus 3 should detect startup against incompatible data directories/files (ie. those with later schema versions compared to the installation attempting to run), fail, and log a SEVERE message indicating the problem into the nexus.log