[Q]About Dragon soul refine

[piticul14 1]

Hello guys
While i trying dragon alchemy i m able to do upgrade class and clarity ..but level of dragon stone ( strength) can t be increase...
Here is the picture

https://postimg.io/image/vj8icvf5r/

If i click too nothing happens..
In sys error i get this(ch1)

DoRefineStrength: INVALID DRAGON SOUL(114410)

any solution for this ?
Thanks in advance...

P.S : I put vnum_range 99 on item_proto(server/client) at dss but doesn t work..