We have Observium configured to use LDAP authentication against our Active Directory instance.  This has been working properly for over a year. 

Beginning this week, the web interface hangs at authentication when LDAP is enabled.  I can revert it to local (mysql) authentication, and it works properly.  However, I can also successfully run an ldapsearch using the same parameters from config.php.  There have been no recent configuration changes on either Observium, or the LDAP server.  

With debugging enabled, I get this message:  

Error binding to LDAP server: ldaps.openfiberky.com: Can't contact LDAP server

Can you assist with further troubleshooting?