Business rule syntax error 1200400

Hello,

I am getting the below error while running a business rule.

1200400	ERROR	Error executing formula for [ACC1] (line 0): scalar double argument expected in function [@EQ ]

here is the syntax:

"CAT2"->"ACC1" = @SUMRANGE ("STAT"->"CAT"->ACC1",@ATTRIBUTE ("ABC-X12-1");

I am trying to allocate the sum of ACC1 account for all entities derived from the attribute "ABC-X12-1" at STAT and CAT level (these are parent members. CAT is stored and STAT is dynamic calc parent) and put it into a CAT2 member (lev 0 in CAT dimension)

Is there any other way to achieve this?