If you have recently configured your Dynamics AX and about to process some transactions that will use your defined ledgers then it is recommended that you configure your Accounts structure and add to your Ledger before you post anything, else you would end up with an info log indicating:
Today, I was stuck in the same problem where I was trying to post a customer Free Text Invoice (FTI), and I received this error while posting it. I checked my posting profile and all other configuration in AR module but I couldn’t find any missing setup there. However, based on little more digging, I found that my account structure wasn’t configured neither activated nor added to my ledger, below is some more detail on how I fixed it.
Configure your accounting structure, Go to
General Ledger > Setup > Chart of accounts > Account Structure.
(Note: Make sure once you are done configuring your account structure, it is activated as well).
When your account structure is configured and activated, Go to General Ledger > Setup > Ledger > click Add button to add your activated Account structure.
(only the active account structures will be displayed under the drop down menu)
This configuration has resolved my problem, hope it will resolve the problem of others too 🙂