Blank dashboard on 'save options' and no connection

We have a CentOS 6 server using nginx for our WP multisite network. We’re trying to use WPMU Ldap Authentication plugin v.4.0.2. I have triple checked all the credentials but whenever we try to “save options” with the “test connection” radio button checked yes, we end up with a dashboard page with top and left side menus but blank results area. We are able to telnet from the server to the ldap server and manually access via CLI command but cannot get a connection through the plugin for our WordPress network.

The ldap server is displaying this message:

conn=1740755 op=-1 msgId=-1 - fd=141 slot=141 LDAP connection from {wordpress IP} to {ldap IP}

conn=1740755 op=0 msgId=0 - RESULT err=80 tag=120 nentries=0 etime=0

conn=1740755 op=-1 msgId=-1 - closing from {wordpress IP} - B1 - Client request contains an ASN.1 BER tag that is corrupt or connection aborted -

conn=1740755 op=-1 msgId=-1 - closed.

Any ideas?

https://wordpress.org/plugins/wpmuldap/