Help with Parameter/Measure

Hi all,

I am trying to create a parameter for use in a slicer, using the following measure

Test =
VAR ClipValue =
    SELECTEDVALUE ( 'Big Deal Clip'[Big Deal Clip] )
VAR PipeNumber =
    CALCULATE (
        SUM ( 'Combined Dataset inc SBU Totals for GSO Calc 2'[CV €M] ),
        OR (
            'Combined Dataset inc SBU Totals for GSO Calc 2'[Stage Group] = "Pipe (Qualified)",
            'Combined Dataset inc SBU Totals for GSO Calc 2'[Stage Group] = "Pipe (Unqualified)"
        ),
        'Combined Dataset inc SBU Totals for GSO Calc 2'[Deal Clip] < ClipValue
    )
RETURN
    GENERATESERIES ( 0, PipeNumber, 1 )

but I get the error message "The arguments in GenerateSeries function cannot be blank"

There is a value selected in the 'Big Deal Clip'[Big Deal Clip] Slicer

If I create a measure using the code that I am trying to get in the max of the GENERATESERIES :

PipeNumber =
CALCULATE (
    SUM ( 'Combined Dataset inc SBU Totals for GSO Calc 2'[CV €M] ),
    OR (
        'Combined Dataset inc SBU Totals for GSO Calc 2'[Stage Group] = "Pipe (Qualified)",
        'Combined Dataset inc SBU Totals for GSO Calc 2'[Stage Group] = "Pipe (Unqualified)"
    ),
    'Combined Dataset inc SBU Totals for GSO Calc 2'[Deal Clip] < ClipValue
)

It returns a value, not a blank - I can't work out why the first formula isn't working and I would greatly appreciated any guidance.

Thank you,

Andrew