Suggested by @MarcoFalke after #14627 and possibly #14420. We should warn if an unrecognised/incorrect section is present in bitcoin.conf. i.e `[testnet]` is present instead of `[test]`.
if (file) {
            LogPrintf("Importing blocks file %s...\n", path.string());
            LoadExternalBlockFile(chainparams, file);
        } else {
            LogPrintf("Warning: Could not open blocks file %s\n", path.string());
        }
    }
    
    CValidationState state;
    if (!ActivateBestChain(state, chainparams)) {
        LogPrintf("Failed to connect best block (%s)\n", FormatStateMessage(state));
        StartShutdown();
        return;
    }
    if (gArgs.GetBoolArg("-stopafterblockimport", DEFAULT_STOPAFTERBLOCKIMPORT)) {
        LogPrintf("Stopping after block import\n");
        StartShutdown();
        return;
    }
    } 
    if (gArgs.GetArg("-persistmempool", DEFAULT_PERSIST_MEMPOOL)) {
        LoadMempool();
    }
    g_is_mempool_loaded = !ShutdownRequested();
}
/** Sanity checks
 *  Ensure that Bitcoin is running in a usable environment with all
 *  necessary library support.
 */
static bool InitSanityCheck()