Diagnosis
You want to revaluate stock at retail without changing the margins.Inventory revaluation at retail that does not affect margins alwaysresults in a revaluation of the stock at cost.
Since the stock of material &V1 is negative, the inventory cannot berevaluated atr cost. The cost method when stock is negative is notallowed.

Procedure
You can revaluate the inventory at retail and manually revaluate theinventory at cost online when the stock is once again positive.
Inventory revaluation without changing the margins is only possible atretail when the stock is positive.