Scenario

Accounting Preference: Allow Transaction Date Outside of Posting Period = Warn or Allow

1. Click Fulfill Button
2. Date is 6/10/2019 (June 10, 2019)
3. Change the PostingPeriod from Jun2019 to May2019 > Save
4. Upon saving ItemReceipt or ItemFulfillment, a notice is thrown:
   'The transaction date is not within the date range of the selected posting period. Click Go Back, then do one of the following:
   
   Enter a transaction date that falls within the date range of the selected posting period.
   
   Choose a posting period that includes the transaction date.'

Solution

As of 2019.1, there is a new feature introduced that controls the posting of Inventory Transactions Outside the PostingPeriod.

1. Navigate to Setup > Accounting > AccountingPreferences
2. Check the box for Allow Inventory Transactions Dated Outside the Posting Period
3. Save

Item Receipts and Item Fulfillments can now be saved with a Date outside the Posting Period.