Could be related to this bug, fixed in 4.1 SP3.
https://bobj-board.org/t/214747/5
I dont know why you would be migrating to such an old patch level and SP1 is not a good choice, in any case.
You are missing the 4.1 SP3 Webi variable re-write functionality for one 
.
Mak 1 
(BOB member since 2005-01-06)