MRP Element "Stock" in MD03 and MD04

Hello MM Expert,

the plant Z001 contains the 2 storage locations SL01 and SL02. there is a quantity 3 of the material 100200 in the store SL01 and an 20 in the store SL01.

the stock of the material100200 in the plant Z001 is 23.

but when the run MRP calculation on the MRP area Z001 (with MD03), the available stock is "0" ZERO! while in the reality the available stock is 23 !!

thank you to explain to me how can I do to get the real available stock of the plant Z001 in the MD03 and MD04? (MRP elemnts STOCK, and Exception message 96).

thank u in advance.

SDA