R12 Month End closure process: When AP sweeps unaccounted transactions does next GL Period need to b

R12 Month End closure process: When AP sweeps unaccounted transactions does next GL Period need to be open?

Reading the white Paper we are unsure if this is required or not.

We are dealing with AP datafixes ongoing from R11 + R12 and seem to have orphaned (cancelled) events. Next GL period was not opened in two Ledger Sets during a recent closure and AP was unable to sweep the few oprphaned events forward to the next period. This prevented AP from closing.

Is there a connection?

Is it best practice to open the next GL Period before the AP unaccounted transactions sweep?