The expression refers to multiple columns. Multiple columns cannot be converted to a scalar value.

[Hayoung]

I have created measure:

Q3 TEST3 = CALCULATE(COUNTROWS ('Q3'),FILTER(FILTER(Q3,Q3[Facility Name]=SELECTEDVALUE(Demographics[Facility Name])),ALLEXCEPT(Q3,Q3[Gender])))

It pop up the error: 

The expression refers to multiple columns. Multiple columns cannot be converted to a scalar value.

Anyone know how should i modify?

[AllisonKennedy]

  What are you trying to achieve?  

You have used the FILTER function twice. The filter argument in the filter function should be a true / false expression - you've used a calculate modifier ALLEXCEPT which can only be used in the calculate function. 

Here's your expression formatted using DAXformatter.com to make it more clear: 

Try either:

Q3 TEST3 =
CALCULATE (
    COUNTROWS ( 'Q3' ),
    FILTER ( Q3, Q3[Facility Name] = SELECTEDVALUE ( Demographics[Facility Name] ) ),
    ALLEXCEPT ( Q3, Q3[Gender] )
)

Or try:

Q3 TEST3 =
CALCULATE (
COUNTROWS ( 'Q3' ),
FILTER (
ALLEXCEPT ( Q3, Q3[Gender] ),
Q3[Facility Name] = SELECTEDVALUE ( Demographics[Facility Name] )
)
)

@Hayoung