Check the SAP note 1580074 - Unable to select line items in Collective release of purchase requistion in transaction ME55
Resolution
- Enter transaction SPRO.
- Select Materials Management.
- Select Purchasing
- Select Reporting.
- Select Maintain Purchase Requsition list.
- Select Define Default values for transaction.
- Activate the field "selection" for transaction ME55.
- Enter transaction ME55.
- Enter release code and selection cirteria.
- Execute.
- Select line item.