So today as I was checking on the update status of all the windows computers the WSUS MMC Console would throw the following error (System.Xml.XmlException — ‘’, hexadecimal value 0x16, is an invalid character). Upon googling this issue I came across a technet article which contained a solution and some improvements on the first provided solution. I will sum it up as follows, this is most likely caused by a computer reporting back information to wsus which contains invalid characters. In the article it was linked back to a DELL BIOS version.

Steps to resolve the issue:

Install the SQL management studio on your WSUS server.

Once installed open up the SQL management studio and connect to the following target: \\.\pipe\MICROSOFT##WID\tsql\query

Open a new query and run the following:

select * from tbComputerTargetDetail a
join tbComputerTarget b on b.TargetID = a.TargetID
where a.ComputerModel like '%' + CHAR(0x16) +'%' 

This should report back the computer with the issue for me it is also a DELL laptop and I will have the BIOS updated but for now as a temporary fix I just edited the special character and replaced it with DELL until my co-worker can update the BIOS.

References
TechNet Forum