Tech Blog

Recently our WSUS console kept crashing either when opening certain computer folders or All Computers.

Error: Unexpected error

So after lots of frustration I rebuild WSUS on Server 2016 and using a proper SQL instance:

Uninstall WSUS PowerShell:

Uninstall-WindowsFeature -Name UpdateServices,Windows-Internal-Database -Restart

Then re-install with powershell:

Install-WindowsFeature -Name UpdateServices-Services,UpdateServices-DB –IncludeManagementTools

Then set the SQL instance using a elevated CMD:

WsusUtil.exe PostInstall SQL_INSTANCE_NAME="SQLSERVER\INSTANCE" CONTENT_DIR=E:\WSUS

The servers all started populating, great.

Then FAIL again.

The WSUS administration console has encountered an unexpected error. This may be a transient error; try restarting the administration console. If this error persists, 

Try removing the persisted preferences for the console by deleting the wsus file under %appdata%\Microsoft\MMC\.


The WSUS administration console has encountered an unexpected error. This may be a transient error; try restarting the administration console. If this error persists, 

Try removing the persisted preferences for the console by deleting the wsus file under %appdata%\Microsoft\MMC\.


System.Xml.XmlException -- '', hexadecimal value 0x16, is an invalid character. Line 1, position 779977.

Source
System.Xml

Stack Trace:
   at System.Xml.XmlTextReaderImpl.Throw(Exception e)
   at System.Xml.XmlTextReaderImpl.ParseNumericCharRefInline(Int32 startPos, Boolean expand, StringBuilder internalSubsetBuilder, Int32& charCount, EntityType& entityType)
   at System.Xml.XmlTextReaderImpl.ParseCharRefInline(Int32 startPos, Int32& charCount, EntityType& entityType)
   at System.Xml.XmlTextReaderImpl.ParseText(Int32& startPos, Int32& endPos, Int32& outOrChars)
   at System.Xml.XmlTextReaderImpl.ParseText()
   at System.Xml.XmlTextReaderImpl.ParseElementContent()
   at System.Xml.XmlReader.ReadStartElement()
   at System.Xml.Serialization.XmlSerializationReader.ReadStringValue()
   at System.Xml.Serialization.XmlSerializationReader.ReadTypedPrimitive(XmlQualifiedName type, Boolean elementCanBeType)
   at Microsoft.Xml.Serialization.GeneratedAssembly.XmlSerializationReaderApiRemotingCompressionProxy.Read1_Object(Boolean isNullable, Boolean checkType)
   at Microsoft.Xml.Serialization.GeneratedAssembly.XmlSerializationReaderApiRemotingCompressionProxy.Read2_GenericReadableRow(Boolean isNullable, Boolean checkType)
   at Microsoft.Xml.Serialization.GeneratedAssembly.XmlSerializationReaderApiRemotingCompressionProxy.Read249_Item()
   at System.Xml.Serialization.XmlSerializer.Deserialize(XmlReader xmlReader, String encodingStyle, XmlDeserializationEvents events)
** this exception was nested inside of the following exception **


System.InvalidOperationException -- There is an error in XML document (1, 779977).

Source
System.Xml

Stack Trace:
   at System.Xml.Serialization.XmlSerializer.Deserialize(XmlReader xmlReader, String encodingStyle, XmlDeserializationEvents events)
   at System.Web.Services.Protocols.SoapHttpClientProtocol.ReadResponse(SoapClientMessage message, WebResponse response, Stream responseStream, Boolean asyncCall)
   at System.Web.Services.Protocols.SoapHttpClientProtocol.Invoke(String methodName, Object[] parameters)
   at Microsoft.UpdateServices.Internal.ApiRemoting.ExecuteSPSearchComputers(String computerTargetScopeXml)
   at Microsoft.UpdateServices.Internal.DatabaseAccess.AdminDataAccessProxy.ExecuteSPSearchComputers(String computerTargetScopeXml)
   at Microsoft.UpdateServices.Internal.BaseApi.ComputerTarget.SearchComputerTargets(ComputerTargetScope searchScope, UpdateServer updateServer)
   at Microsoft.UpdateServices.UI.AdminApiAccess.ComputerTargetManager.GetComputerTargets(ComputerTargetScope searchScope)
   at Microsoft.UpdateServices.UI.AdminApiAccess.BulkComputerPropertiesCache.GetAndCacheComputers(ExtendedUpdateScope updateScope, ComputerTargetScope computerTargetScope)
   at Microsoft.UpdateServices.UI.SnapIn.Pages.ComputersListPage.GetListRows()

After some Googling I found the problem seems to be with a corrupt PC checking in, i.e. the PC checks in, then via WMI all the info is gathered on the PC and if that info is corrupt then WSUS crashes!!

To fix,

Copy the WSUS console error into Notepad++ (don’t use anything else) and look for:

System.Xml.XmlException -- '', hexadecimal value 0x16

Basically this means that the weird square symbol or SYM symbol is present in the WSUS database and causing WSUS to shit itself:

So we need to find it, open SQL Management Studio and open the SUSDB

Note: if you’re not using proper SQL then open the DB via:

\\.\pipe\MICROSOFT##WID\tsql\query

Changed the default view setting by going to the Tools > Options > SQL Server Object Explorer settings, then adjusted the ‘Value for Edit Top <n> Rows command’ from 200 to 0, making the option display all rows.

Navigate down within the SUSDB database, to the dbo.tbComputerTargetDetail table, right-clicked it, and selected ‘Edit All Rows’.

Click the top left corner of the column/rows to select everything, then copy-pasted it into NotePad++

Then copy the SYM from the error and search for it in the info you’ve just copied:

As you can see the ID on the left is 525:

Lets now cross reference this against another table in the SUSDB database via SQL script:

Select * from dbo.tbComputerTarget

Look for the ID:

Thats the PC!!!

Find it and update the BIOS and anything else you can, then get it to report in again to WSUS:

wuauclt /scannow
wuauclt /detectnow
wuauclt /r /ReportNow

Credit to SterlingT, he’s a wonderful human being:

https://social.technet.microsoft.com/Forums/windowsserver/en-US/90dc15d3-c498-42b8-b36a-bd29be35cf99/wsus-console-unexpected-error-when-choosing-all-computers-folder?forum=winserverwsus