OAB – Oh Boy! Yet another annoying error conquered

Exasperation no more!  OAB 0x80190194 error solved - finally

As many of you already know, I do a lot of Exchange configuration in my day to day job (see disclaimer below).  From time to time, I run into errors that seem to occur over and over, regardless of the environment, until someone can finally figure it out.  Outlook attempting to download the Offline Address Book (OAB) has usually been one of those odd errors, especially when a server is first created.

Starting in Exchange Server 2003, the OAB was only generated for the first time when the server entered the first maintenance window after installation.  So if you built a brand new Exchange environment, you would need to wait until somewhere between 1 and 3 AM before you had an OAB.  This meant that Outlook clients would exhibit a strange error about "File Not Found" during every synchronization.  Outlook went to look for an OAB to download, there was none there, and the sync would abnormally end.

This was easy to fix, however.  You simply located the OAB in the Exchange Management tools and forced a rebuild, which immediately cleared up the problem.  In rare circumstances you followed the TechNet articles and removed the OAB and created a new one, then forced a rebuild.  All in all, not a very difficult fix, but one that eludes many Exchange Engineers and Administrators for hours and hours until they either figure out the fix from reading about it on forums; or the give up in frustration and see the miracle of the error going away the next day (since the OAB auto-rebuilt during the night).

When Exchange Server 2007 came along, I had hoped that this would be a thing of the past.  After all, the least that Microsoft could do would be to put a message in the installer about having to rebuild the OAB. The best would be to have it auto-generate immediately on install.  Alas, as most of us in the Exchange world figured out, neither is the case.  On a new Exchange build, you still have to manually force an update of the Offline Address Book.

It is a lot easier now, though.  One Powershell command does it all:

Update-OfflineAddressBook -id "Default Offline Address Book"

Since the first OAB is always "Default Offline Address Book", the command is universal and can just be done immediately on finalizing your installation of the Exchange software.

All was well until I started getting a stream of calls from colleagues across the country about a new error cropping up in Exchange 2007 and Outlook 2007.  These folks had already regenerated the OAB manually or waited until after the first maintenance window, and now - unlike the File not Found errors before - they were getting a very odd error indeed:

Task 'Microsoft Exchange' reported error (0x80190194) : 'The operation failed.'

Google searches turned up suggestions for Microsoft Update, the Windows Update Site, and a few other red herrings.  Further investigation led only to the usual recommendations to regenerate the OAB.  This was driving many people, including me, nuts!  Remarkably, for several months none of us found an answer, but in all cases the problem went away on its own. Sometimes in a few days, sometimes in a few weeks, but always resolved itself in time. 

Now, my readers know me, that's not quite good enough for my palate.  So when time finally permitted I did some deeper investigation.  I found several things out that had nothing really to do with the error, but are fun:

- Avira Antivirus considers Experts-Exchange.com a phishing site.

- People tended to suggest everything short of lighting candles, standing on your head and typing mysterious incantations into Powershell (though frankly some of the stuff was pretty close)

- Many folks just let it go away on its own and never though about it again - until they had to build a new Exchange system.

Finally, I tripped over the MSServerAdmin site and to this article:

http://www.msserveradmin.com/how-to-overcome-the-exchange-2007-oab-issues/

Which got me to look at the Microsoft Exchange File Distribution service on my Client Access Role server (which in my case was on the same box as the Mailbox Role).  Once I stopped and started that service, Outlook immediately began to download the OAB and all was well once again.  That's really all there is to it.  This only seems to happen on Server 2008, which explains why I wasn't seeing it back when most folks were installing Exchange 2007 to Windows 2003.  I do not have an answer as to why this problem is so common with Server 2008, but if any of the Microsoft folks who read this can tell me, I'll happily post an update.

So, why did it go away mysteriously by itself over time?  That was a little more of a quandry, but I got that answer too.  These days, it's not usual to have to reboot an Exchange 2007 server after installation is finalized.  So folks were not restarting services regularly by rebooting the boxes regularly.  However, eventually, Windows Update Services would download a critical OS patch, and - left to its own defaults - automatically reboot the box.  This might happen the next day, or might be several weeks away, but eventually we'd reach Patch Tuesday and the boxes would reboot - restarting the service and clearing the problem.

Good things come to those who wait - this time.  Hopefully the answer will always be as simple as "Just wait and it'll fix itself," but until then I shall keep searching for answers and reporting them here.