Mass Alocation Formula

Hi

I'm trying to set up a mass allocation as follows:

A BGAL.7014.2030.T.YSSEX.T.T.T.T

C.C.C.L.L.L.L.L.L

B 25

C 100

T  BGAL.7014.2000.T.64838.T.T.T.T

C.C.C.L.C.L.L.L.L

O  BGAL.7060.2000.T.64838.T.T.T.T

C.C.C.L.C.L.L.L.L

It passes validation, however when I generate it, it completes with an error - Line A: Looping segment type does not match target line segment; it must                                                   

What I am trying to achieve based on the PTD balances in the accounts from Line A is to allocate 25% to the target account - credit entry and then the debit side of the entry to the offset account