Calendar sync stopped working: "Unable to process organizer data"

Question

I'm trying to help a consulting client whose Blackberry Q10 stopped synchronizing calendar data 5 days ago. It looks like that's the only thing he synchronizes with his desktop. I've tried looking up answers, but I've found very little information about this problem, and the few suggestions I found have not worked.
Phone: Blackberry Q10
Model#: SQN100-2
Software Release: 10.1.0.4189
Blackberry Link Release: 1.2.1.31
Symptoms: After clicking on the Sync Contacts/Calendar button, Blackberry Link sits for a very long time on the "Syncing your contacts and calendar appointments. Do not disconnect your device." screen, with sporadic activity on the progress meter, before being returned to the Sync Contacts and Calendar Appointments screen. In the lower left, a warning message "Sync was unsuccessful" is displayed. When I click the Show Recent Activity link under that, a Recent Activity screen that repeats "Sync was unsuccessful" along with a second message, "Unable to process organizer data" appears.
Is there a way to resolve this short of restoring the phone to factory defaults? The calendar data on my client's phone has now gone 5 days without being synced, and he doesn't want to lose the latest changes.

Answer 1

HipsterZ10, I didn't mean to suggest that you aren't entitled to gripe, only that doing so in response to a post on a community support forum isn't particularly useful. (Do BlackBerry support teams even monitor this forum?)
You sound like someone who knows his way around BlackBerry very well, and I would love to do some brainstorming with you if you're so inclined. I have nowhere near as much BlackBerry experience as you have, but I have worked in many areas of computing support for over 25 years. I'd like to think that between the two of us - plus anyone else who can chime in with something constructive - we can come up with something that helps us all out,.
With that in mind:
You've tried uninstalling and reinstalling without success. Did you just uninstall and reinstall the latest version of BlackBerry Link, or did you try uninstalling the latest version and going back to one that used to work? (Or did you try upgrading because the previous version stopped working?)
Did you try any direct edits to the Registry to clean out any BlackBerry settings that the uninstall program might've left behind? Uninstallers are often not kept up to date as software developers make changes to software, so they often leave digital detritus in the Registry. This usually has no effect on anything else, but can prevent software that was uninstalled from working properly when it's reinstalled.
You also mention that you've tried a lot of settings changes. Would you please share with us the settings changes that you made?
I know from other companies' devices that updates to the Windows software is sometimes accompanied by firmware or programming changes on the device. Does anyone know if that's the case for BlackBerry Link updates? If it is, then simply uninstalling BlackBerry Link may not be enough.
Have you been unable to sync only the calendar, or your contacts as well? (I don't know what else BlackBerry Link can synchronize.) My client has only been trying to sync his calendar. If the problem is confined to calendar sync, is there maybe a cleanup procedure that needs to be run on the device or on the Windows side to clean up old appointments every now and then? I know of other products that will fail to sync their calendars if there's too much old data.
Finally, does BlackBerry Link just sync the BlackBerry device with itself, or does it sync it with Outlook? That wasn't clear to me the last time I was in my client's office; he uses Outlook 2003, but I wasn't certain if BlackBerry Link was connected with it in any way. Come to think of it, my client also uses Windows XP, which does not come with the .NET framework by default. Some commercial software depends on particular versions of the .NET framework, and I've seen situations in which Microsoft updates to the .NET framework breaks 3rd party software. Does BlackBerry require .NET, and, if so, does it try to install the version it needs? To sum these things up, we could be looking at lack of support for older versions of Windows, Outlook  or the .NET Framework.
Those are some ideas; let's see if we can narrow down the list. I should be back at my client's office on Monday, but if anyone else has time to try any of this today, kindly post what you discover here.