I opened up the DB Manager on the server and the below works giving me a list.
SELECT TOP 10 * FROM [dbo].[Interfaces]
where Caption Like '%MPLS%'
I see in my original post I was using *, but when I changed to % I still get the same error, but it seems to work in DB manager.
Could you please try:
Interfaces.Caption Like '*MPLS*'
That works as well as using FullName Like '*MPLS*' by itself.