It looks like the query for report "Error: DNS error" has an error.
The query currently reads:
SELECT     TOP (1000000) dbo.tblerrors.Computername, dbo.tblComputers.ComputerUnique, dbo.tblerrors.ErrorText, MAX(dbo.tblerrors.Lastchanged) 
                      AS [Last changed]
FROM         dbo.tblerrors INNER JOIN
                      dbo.tblComputers ON dbo.tblerrors.Computername = dbo.tblComputers.Computername INNER JOIN
                      dbo.web40ActiveComputers ON dbo.tblComputers.Computername = dbo.web40ActiveComputers.Computername
GROUP BY dbo.tblerrors.Computername, dbo.tblComputers.ComputerUnique, dbo.tblerrors.ErrorText
HAVING      (dbo.tblerrors.ErrorText = 'like %dns redirected%')
ORDER BY [Last changed] DESC
but it should be:
SELECT     TOP (1000000) dbo.tblerrors.Computername, dbo.tblComputers.ComputerUnique, dbo.tblComputers.Domain, dbo.tblerrors.ErrorText, MAX(dbo.tblerrors.Lastchanged) 
                      AS [Last changed]
FROM         dbo.tblerrors INNER JOIN
                      dbo.tblComputers ON dbo.tblerrors.Computername = dbo.tblComputers.Computername INNER JOIN
                      dbo.web40ActiveComputers ON dbo.tblComputers.Computername = dbo.web40ActiveComputers.Computername
GROUP BY dbo.tblerrors.Computername, dbo.tblComputers.ComputerUnique, dbo.tblComputers.domain, dbo.tblerrors.ErrorText
HAVING      (dbo.tblerrors.ErrorText like '%dns redirected%')
ORDER BY [Last changed] DESC
adding both the Domain column and correcting the HAVING clause.  As written it doesn't return any values for me.