Norton Antivirus, Live Update Failed, Operation Failed 8900,213

For a number of weeks now, every time I try to run Live Update, the LU window tells me "Live Update Failed". When I click on the link "Tech Support", it tells me "Operation Failed 8900,213".

 

How can I fix this? I am concerned about the security of my machine.

 

Thank you and best

 

Karsten