Error after upgrading MessageStats "Unknown data processor" (4276310)

After upgrading MessageStats to the latest version you receive the following error when running tasks.

The following error occured in the initialization of a processing component: Unknown data processor
Time Component HResult EventID
2013-08-06T06:54:46.527Z Internal Processing 80070057 {088E2045-F8B7-4E74-B5C5-3291CCD88D8E}

Upgrade all installed Report Packs to the version included with your MessageStats download.

The Report Packs can be found in the MessageStats download folder\ReportPacks.

If the Report packs are upgraded and you have confirmed the DLL files of the Report packs to be the latest version, try the following:

1. On the MessageStats Scheduler server, remove the gsc.xml file located here by default:

C:\Program Files (x86)\Quest Software\MessageStats

2. Restart the MessageStats Service.

3. For the troubled task, right click | Properties

4. Then click next all the way through the Wizard until it closes. (That will resave the task)

5. Run the Gathering task that is throwing the error.