Hi,
As you re-designed your release strategy with release codes - you are having this message!
Before changing existing release strategies setting - you should have released all old purchase requisitions with old release values with old release strategy with release codes and then related transport request number transported with your new release strategies with release codes setting.
As you are middle of process and now just change all old purchase requisitions(ME52N)
without changing value and quantity--have ONLY text changes to triggers your NEW Release Strategy with NEW release codes to release all old purchase requisitions.
Regards,
Biju K