Use FilterMembers() to filter the source UD1, and remove UD1 from the destination intersection, as expansion/filter functions are not valid in any intersection definition.
If U4#All_Projects is a parent member, then remove it from both the source and destination intersections, as you cannot write to a parent member. If the formula must be applied to the All_Projects member, then specify that on the source side, but specify a U4# base member on the destination side.
Why are you referencing so many dims in your intersections? Time as an example is totally pointless to include.
