Query pattern problem

I have been getting this error with some LINQ expressions:

Could not find an implementation of the query pattern for source type 'System.Text.RegularExpressions.MatchCollection'. 'Where' not found. Consider explicitly specifying the type of the range variable 'v'

You get this error because MatchCollection implements only IEnumerable and not IEnumerable(Of T) All you need to do is change:

from v in ex.Matches(template)

to:

from Match v in ex.Matches(template)

I.e. do what it says and specify the type of the range variable.