Code review comment: `internal error` message is not suitable

Code under review:
private StorageVolume getStorageVolumeOfTable(String svName, long dbId) throws DdlException {
        StorageVolume sv = null;
        if (svName.isEmpty()) {
            String dbStorageVolumeId = getStorageVolumeIdOfDb(dbId);
            if (dbStorageVolumeId != null) {
                return getStorageVolume(dbStorageVolumeId);
            } else {
                sv = getStorageVolumeByName(BUILTIN_STORAGE_VOLUME);
                if (sv == null) {
                    if (Config.enable_load_volume_from_conf) {
                        LOG.error("Failed to get builtin storage volume, svName: {}, dbId: {}, current stack trace: {}",
                                svName, dbId, LogUtil.getCurrentStackTrace());
                        throw new DdlException("Internal error");
                    } else {
                        throw new DdlException("Cannot find a suitable storage volume. " +
                                "Try setting 'enable_load_volume_from_conf' to true " +
                                "and ensure the related storage volume settings are correct");
                    }
                }
            }
        } else if (svName.equals(StorageVolumeMgr.DEFAULT)) {
            sv = getDefaultStorageVolume();
            if (sv == null) {
                throw new DdlException("Default storage volume not exists, it should be created first");
            }
        } else {
            sv = getStorageVolumeByName(svName);
            if (sv == null) {
                throw new DdlException("Unknown storage volume \"" + svName + "\"");
            }
        }
        return sv;
    }

Line commented on: throw new DdlException("Internal error");

Revised code:
private StorageVolume getStorageVolumeOfTable(String svName, long dbId) throws DdlException {
        StorageVolume sv = null;
        if (svName.isEmpty()) {
            String dbStorageVolumeId = getStorageVolumeIdOfDb(dbId);
            if (dbStorageVolumeId != null) {
                return getStorageVolume(dbStorageVolumeId);
            } else {
                sv = getStorageVolumeByName(BUILTIN_STORAGE_VOLUME);
                if (sv == null) {
                    if (Config.enable_load_volume_from_conf) {
                        LOG.error("Failed to get builtin storage volume, svName: {}, dbId: {}, current stack trace: {}",
                                svName, dbId, LogUtil.getCurrentStackTrace());
                        throw new DdlException(String.format("Failed to get builtin storage volume, svName: %s, dbId: %d",
                                svName, dbId));
                    } else {
                        throw new DdlException("Cannot find a suitable storage volume. " +
                                "Try setting 'enable_load_volume_from_conf' to true " +
                                "and ensure the related storage volume settings are correct");
                    }
                }
            }
        } else if (svName.equals(StorageVolumeMgr.DEFAULT)) {
            sv = getDefaultStorageVolume();
            if (sv == null) {
                throw new DdlException("Default storage volume not exists, it should be created first");
            }
        } else {
            sv = getStorageVolumeByName(svName);
            if (sv == null) {
                throw new DdlException("Unknown storage volume \"" + svName + "\"");
            }
        }
        return sv;
    }