Can't set notification topic using mosquitto bridge

[ilyaroot]

Instance type: hosted
User ID: u22

Previously, I've used the following lines in my mosquitto gbridge config:

notifications true
notification_topic bridge/gbridge

Expected behaviour:
Topic bridge/gbridge gets '1' message, when my mosquitto connected to hosted service.
Actual behaviour:
mosquitto gets "Socket error" message and connection fails.

Is this behaviour now due your MQTT server settings?