Working Access Query Fails When Using Excel Data Connection

I've about 10 pivot tables in Excel that are populated via an External Query link to Access. In each case I have pre-written views with all the columns I need so that the query can just pick them up. Nine of the ten queries work perfectly, but one doesn't - reporting "Too Few Parameters - Expected 1" when I try and click on the "Return Data to Excel" in the import wizard.

I can see the column headers in Excel to select; so I'm assuming that it can parse the SQL but no results are being returned. Just to confirm though - results are returned (>8000 of them) in Access.

SQL code below:

Code:
SELECT z.pathdurationhours AS PathHours, Count(z.pathdurationhours) AS Paths,
Count(z.pathdurationhours)/(select count(*) from (select [activity date],
[conversion ID], count(*) from tbl_dfa_p2cdata group by [activity date], [conversion ID]) ) AS PCT
FROM (SELECT a.[activity date], a.[conversion ID], val( max(a.[interaction time])-min(a.[interaction time]) )
*24 AS PathDurationHours FROM tbl_dfa_P2CData AS a WHERE a.[interaction time]
"" GROUP BY a.[activity date], a.[conversion ID]) AS z
GROUP BY z.pathdurationhours;