2838582 - Error M7115 posting difference into previous period

You have created a Physical Inventory document for one or more materials. When you try to post the count difference into the previous period you receive error message, 'Back-posting only poss. w. same val. class' (M7115)

SAP S/4HANA Cloud Public Edition All versions

Open the tile 'Create Single PI Document'.
Enter the required data and save the PI Document. 
Open the tile 'Enter Inventory Count'. 
Enter the required quantities and save the update.
Open the tile 'Post Physical Inventory Document'.
Set a posting date in the previous period. 
Enter a difference reason and press POST. 
Error 'Back-posting only poss. w. same val. class' is raised.

Changes have been made to the valuation class of the material. The system checks the valuation class of the current and previous periods, MBEW-BKLAS and MBEW-VMBKL. 
If a difference is found the posting is stopped with this hard coded error M7115, to avoid database inconsistencies.

This is not a customisable message, it cannot be avoided you have to post the difference into the current period.

MBEW-BKLAS, MBEW-VMBKL, MARV, MI07, MI20, MI04, , KBA , MM-IM-PI-PI , Physical Inventory , MM-IM-PI-PI-2CL , Physical Inventory (Public Cloud) , Problem