The user was creating Payables Manual Checks with SmartConnect and letting eConnect default the distributions for the check by setting the Create distributions mapping to 1.
The checks integrated successfully.
However, when running the Edit List and looking in the Dynamics GP Payables Transaction Entry Distribution window, no distributions were actually created so the document would not post.
The issue was that the user was providing their own Voucher Number instead of using a GP Rolling Column. The Voucher Number provided was 18 characters and the maximum value that can be hand-entered into the Payables Manual Payment Entry window is 17 characters.
When we changed the source data to only use a 17 character voucher number, eConnect created the Manual Payment and also created the expected distributions for the document.