Using DMT to import BOO

I am using DMT to import a bunch of Bill of Operations from another version. Most of them import correctly, but about 1% of them error out with this:
(ECOOprBeforeUpdate) Table ECOOpr Cannot change the SubContract flag once set."

How could the subcontract flag already be set if I am importing new BOOs? It seems to marking most BOOs correctly as subcontract operations (if they are), but then these error ones are not being marked as subcontract when they should be.

What am I missing?

Not sure if it is still an issue with DMT, but back when we imported BOM’s we discovered that the MtlSeq we provided was being ignored. It would take the first line and make it 10, the second 20, etc …

So if our BOM had the following

SEQ PartNum
10  ABC-123
15  ABC-999
20  ABC-321

It would import as

SEQ PartNum
10  ABC-123
20  ABC-999
30  ABC-321

If the lines related ot other info, by MtlSeq, you may get errors when the 2nd line is now 20, and trying to relate to info that was for the original 3rd line.

As it turns out, we were importing data from Vantage 5.2 which allows the same operation to be either inside or outside labor. But Epicor 10 only allows an op to be one way or the other, so I had to prefix all of my outside ops with OS- and then this error went away.