Invoice line with source as OKS Contracts created with Accounting Rule Duration as 0

Hi,

I have a service contract with a total duration of 3 months and monthly billing schedule with advance invoicing.
On running autoinvoice import for it, the invoice line is populated with accounting rule duration as 0.
I had a new accounting rule for it with below setups -
1. Type as Daily Revenue Rate, Partial Periods
2. Period as Month (same as GL calendar period)
3. Under Schedule - Period 1 with 0 percent

Please advise if there is an issue with the accounting rule setup or if there is some other issue. On running Create Accounting for the invoice, error is received that No Accounting can be created for this document.