I'm running Exchange 2013 CU2, and i could never get OWA Search to work or stay stable. I found an article, http://www.techieshelp.com/exchange-2013-outlook-and-owa-search-does-not-work/
that tells you to rename the GUID.single folder so that outlook will rebuild the search from scratch. That worked and database now says healthy.
My main issue is now because of that is "some users" can no longer connect to exchange via outlook 2010/2013, while some PCs are still connected to exchange. My self included, running Outlook 2010, will not connect. I tried to make a new profile, but then it says "connection to Microsoft exchange is unavailable"
I must note that the users that are still "connected" to exchange via outlook, i had them send an email to another mailbox in the system, and the mail never arrives even tho it shows it as sent.
I also noticed if you send an email from OWA, it goes into your draft folder.
any ideas? i tried rebooting and restarting services.