Today I got the same error message in AX 2012 R3.
I checked the main account and in the field "Select the level of main account to display" it was set to Companies
Additionally, in the Financial Dimension quick tab ,we have a financial dimension with "Fixed Value".
However, when I created the payment proposal, the financial dimension fixed to the main account was missing in the "Offset account" field. It was just a combination of Main account and Intercompany key, but without the consolidation account.
To solve this problem, make sure that you add a Default offset account type and Default offset account whyn you create the payment proposal.
- Default offset account type: Ledger
- Default offset account: the particular account
For some reason AX adds the financial dimension to the line and then the journal can be posted.