optimization of energy management system _problem objective error

Hi,

i am getting error for below code of optimisation objective:

An error occurred while running the simulation and the simulation was terminated

Caused by:

• Objective must be a scalar OptimizationExpression or a struct containing a scalar OptimizationExpression.Please help

prob.Objective =dt*Price'*PbattupsV +dt*Price'*PbattdchV*Nb_dch1V'+ dt*Price'*PbattchV*Nb_ch1V' ;