MDX FORMULA - HIERARCHY ERROR

Hello,

BPC 10.1 nw ,hana mdx enabled.

Member formula:

IIF([ENTITY].CURRENTMEMBER=[ENTITY].[PC_ASA],10,20)

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[ENTITY].[PC_ASA] - This member is only in H2 hiearachy.

above member formula works only when i select an entity from H2.if i select an entity from H1 , report throws an mdx error "no result set..".

is there any syntax error in the formula? or is it a system bug.

thanks in advance.

Rekha