Records stuck in SLA for Period close Variance after period closed.

Hi,

Records are get stuck in SLA table every month after period closed for WIP transaction as period close variance.

we are getting following accounting entry is passed

DR: Work In Process Variance

CR: Work In Process Valuation

And getting following 'error' from SLA accounting events:

Event class = WIP Variance
Event Type = Period Close Variance
Event Status = Error

Error Details: The GL date is not in an open or a future enterable period. Please select a valid GL date or open the period.

Please suggest how to deal with this error and what is the root cause.

Regards,

Dipak