Diagnosis
An error occurred as the selected deliveries were being locked. Eitherone of the deliveries involved is being processed or there is an errorin lock management.

System Response
If group output processing is defined for the group type, the systemlocks the deliveries that are to be put together in that group to makesure that the deliveries involved are not currently being processed. Inthis case, the deliveries cannot be refreshed (during dispatch ofpicking output, for example). The multiple block is lifted before theoutputs are updated.

Procedure
Make sure that none of the selected deliveries are currently beingprocessed and then attempt the action again.