Lots of the same error in the logs

I just finished upgrading from OF 3.9.2 running on OS X to OF 3.10.2 on a Centos 6.6 VM, and while most of the upgrade went smoothly, we’re starting to get reports from our most demanding users that they’re seeing slowdowns of the service during peak usage hours.

I’ve adjusted some of the cacheing settings to alleviate a few bottlenecks, but we’re still seeing slowdowns, and I’m seeing a whole lot of a few specific error messages in the error.log file:

2015.08.19 16:22:52 org.jivesoftware.openfire.muc.spi.MultiUserChatServiceImpl - Internal server error

java.lang.IllegalArgumentException: IQ must be of type ‘set’ or ‘get’. Original IQ: <iq type=“error” to="ccrtc@rooms.jabber…

and

org.jivesoftware.openfire.muc.spi.MultiUserChatServiceImpl - Internal server error

java.lang.IllegalArgumentException: IQ must be of type ‘set’ or ‘get’. Original IQ: <iq type=“result” id=“iChat_73FF3EEF” to="ccrtc@rooms.jabber…

and also

org.jivesoftware.openfire.ldap.LdapManager - invalid attribute description

javax.naming.directory.InvalidSearchFilterException: invalid attribute description; remaining name ‘’

I’d really like to resolve these errors so that I can definitively tell the customer that the issue is with networking connectivity, and not with this server (which is idling at less than 10% CPU usage and under 1Mbit traffic even at peak times under a load of around 4000 users.)

Is there anything else I should be looking at to attempt to resolve these slowdowns?

Anyone?