Resolve error Vault [CONN_STATE] reason [nbio connect error] in EngageOne Vault

Issue

The errors below is encountered in the e2loaderd log. The documents are ingesting but are not visible in searches.
 
10:09:07 finished indexing document file [docdata\20140214-90000000002896.drd], [0] errors
10:09:07 <connection1> notice.cacheflush request
10:09:07 ERROR 71101: code [0x02002741] library [system library] function [connect] reason [unknown]
10:09:07 ERROR 71101: code [0x2007306E] library [BIO routines] function [CONN_STATE] reason [nbio connect error]
10:09:07 ERROR 71117: unable to connect on socket, error [0]
10:09:07 <connection1> ERROR 70310: socket failure connecting to [0.0.0.0:6001], error [71101]

Cause

The e2serverd might not be running, or not running on the expected port (in this case port 6001).

Resolution

UPDATED: March 27, 2018
In order to resolved this, ensure that e2serverd is running on the correct port.

Also check to make sure that nothing else on the machine is using that port number.

Make sure that the port isn't getting blocked.