If function in a Do While loop, which bug at the end (I'm new) runtime error 13 type mismatch

Public   Sub   TFE()
Const C_R_S  =  13
'Now,we will iterate to draw the FE
bMax  =  False
i  =  2
j  =  C_R_S


Do While  ( Not ( IsEmpty ( Cells ( i , j ) ) )  And  bMax  =  False )
'we set the desired return
Cells  ( 98 , 5 ) .Value =  Cells ( i , j )
'we optimize the variance accordingly
Call  OptimiseVolPF
'we recover the return
Cells ( i , j +1 ) .Value =  Cells  ( 97 , 3 )
'we get the annual variance
Cells ( i , j + 2 ) .Value = Cells ( 100 , 3 )
i  =  i + 1
'if we have not managed to improve, then we stop
   If  i >  3  And  Cells ( i - 2 , j + 1 ) .Value =  Cells  ( i + 2 , j + 1 ) .Value   Then bMax   =  True
Loop


End sub