Illegal 'activate' predecate

I am creating a orch that has filter on the initial receive shape. When building I got these error: Error 1 : identifier 'MySolutionname' does not exist in 'MyOrchName'; are you missing an assembly reference? Error 2: cannot find symbol 'MySolutionname' Error 3: an 'activate' predicate rvalue must be a string, character, boolean or numeric literal Error 4 : illegal 'activate' predicate The solution to this is to put the filter expression in sting literals (i.e. “double quotes”)