[horde] Error communicating with server during search

[Mike]

Had a recent upgrade on my server and got an "Error communicating with  
server" when trying to do a search for an e-mail.

I'm happy to troubleshoot this, but really don't know where to start  
since all the other functions seem to work as I have known them to.

For example, I can get and read messages, send them and use active-sync.

Using "doveadm search..." on the mailbox returns records, so I don't  
think it is the mail servers issue.

I turned on test.php and it didn't reveal anything obvious.

What should I do next for further troubleshooting?