Sales Order line status is "Awaiting Invoice Interface - Incomplete Data". Unable to create RMA Credit Memo in AR

Solution 1:
Query the Sales Order, The Sales order Line status will be " Awaiting Invoice Interface - Incomplete Data"
Now go to 'Actions' > 'Progress Order' > Choose 'Invoice Interface - Eligible'.

Then Sales Order Line Status will be"Closed"

Now the 'Autoinvoice Master Program' and 'Autoinvoice Import Program' will be launched automatically. Check the invoice in the AR.

Solution 2:
Query your OM Transaction Type and check whether AR Transaction Source and Transaction Type are assign to it or not.
If not assigned, assign it and run the workflow background process program.
Now the 'Autoinvoice Master Program' and 'Autoinvoice Import Program' will be launched automatically, and invoice will be generated.