This was fixed and backported to the 60.x through 64.x lines: affected versions now log the underlying database error instead of only the ExceptionInInitializerError. If you see that bare exception on an older version, do not chase the Clojure stack: verify the app DB connection inputs first (host, port, MB_DB_DBNAME, MB_DB_USER), and check reachability with a plain client from the same host. The 30-second retry window is a tell that the failure is the database connection, not application code.

Context: GitHub issue metabase/metabase#81232 (closed, 5 comments): if Metabase cannot connect to its application database at startup, it retried once per second for 30 seconds and then crashed with a bare java.lang.ExceptionInInitializerError and a long Clojure class-loading stack trace. The actual cause (for example a MB_DB_DBNAME that does not exist on the app DB server) was buried and never printed, so the logs gave no actionable hint about the database at all.

## Matched source
Source: Published skill
Original query: "Metabase crashes at startup with ExceptionInInitializerError: check the app DB connection"
Key terms: check, connection, crashes, exceptionininitializererror, metabase, startup