When viewing Server Manager on Windows Server 2008 we are getting a Roles: Error with error details of unexpected error refreshing Server Manager and an exception code: 0x800B0100.

Solution:

1. Download System Update Readiness Tool for Windows Server 2008/Vista – http://support.microsoft.com/?kbid=947821

x86

http://www.microsoft.com/downloads/details.aspx?FamilyID=6d9ece65-3820-4583-85f5-7e2a5799b3ba&DisplayLang=en

x64

http://www.microsoft.com/downloads/details.aspx?FamilyID=32978546-8108-408f-b78e-0e95eff14c92&DisplayLang=en

2. The System Update Readiness Tool creates a log file with any issues the tool found or fixed.
The log file is located under: c:\windows\logs\CBS\CheckSUR.log

Example:

=================================
Checking System Update Readiness.
Binary Version 6.1.7600.20822
Package Version 10.0
2010-12-17 17:39

Checking Windows Servicing Packages

Checking Package Manifests and Catalogs
(f)    CBS MUM Corrupt    0x00000000    servicing\Packages\Package_for_KB2388210_RTM~31bf3856ad364e35~amd64~~6.1.1.1.mum        Expected file name Microsoft-Windows-Foundation-Package~31bf3856ad364e35~amd64~~6.1.7600.16385.mum does not match the actual file name

Checking Package Watchlist

Checking Component Watchlist

Checking Packages

Checking Component Store

Summary:
Seconds executed: 343
Found 1 errors
CBS MUM Corrupt Total count: 1

Unavailable repair files:
servicing\packages\Package_for_KB2388210_RTM~31bf3856ad364e35~amd64~~6.1.1.1.mum
servicing\packages\Package_for_KB2388210_RTM~31bf3856ad364e35~amd64~~6.1.1.1.cat

Based on the example this means that we are missing 1 MUM packages under c:\windows\servicing\packages

3. We locate the failed KB Update KB2388210 in this example which will be different for everybody and we download it on our system
4. We rename it from .msu to .cab and we extract it to get our missing files
5. We locate the missing files and we copy them to a new folder. Most of the times at least 1 file can not be found so we have to rename the update.mum and update.cat to the missing file name

6. We select Properties of c:\windows\servicing\Packages and under Security tab we click on Advanced. On Owner tab we click on Edit and change the owner from TrustedInstaller to our account and then OK to return back to Packages Properties
7. Under Security Tab we click on Edit so we can add our account with Full control
8. Now we copy the missing files to c:\windows\servicing\Packages
9. We rerun the update until the log file does not report any more missing files

* Do not forget to assign the Package permissions back to NT SERVICE\TrustedInstaller after you finish with the updates.