Do I have to use Elasticsearch in Pro 7.x?

Hello:
I am using seafile-pro-server_7.0.9_x86-64_Ubuntu now.
I want to use build-in search so I disable Elasticsearch like this:

[INDEX FILES]
enabled = true
interval = 10m
external_es_server = false

but the search function doesnt work.
When I want to update the index manually, an error was thrown:

elasticsearch.exceptions.ConnectionError: ConnectionError(<urllib3.connection.HTTPConnection object at 0x7f34b250eb90>: Failed to establish a new connection: [Errno 111] Connection refused) caused by: NewConnectionError(<urllib3.connection.HTTPConnection object at 0x7f34b250eb90>: Failed to establish a new connection: [Errno 111] Connection refused)

So I cannot use build-in search function any more?

Right. You can not.