Problem

Solution
When we are trying to create a sales order or an invoice the posting period errors occurs due to the accounting period is closed. We cannot make make any changes if the the accounting period is closed. To solve this issue we need to setup accounting period for a full year. Do the following steps to achieve the solution
- Go to Setup > Accounting > Manage G/L > Manage Accounting Periods.
- Select a fiscal calendar.
- Click Set Up Full Year.
- On the Accounting Periods for a Full Year page, verify that the Fiscal Calendar is correct.
- The first fiscal month for the fiscal calendar displays, defaulting from the fiscal calendar selected.
- Select the format you want to use for your accounting periods: Calendar Months, 4 Weeks, or 4-4-5 Weeks.
- In the Year in Period Name field, select the starting or ending year to include in the period name.
- Optionally, check the One-Day Year-End Adj. Period box to include an adjustment period at the end of this fiscal year. The adjustment period always overlaps the last day of the month.
- Click Save.
After set up Full year it will be reflected in the sales order and invoice record creation pages. the posting periods will automatically change and then we can create the sales order or invoice easily.