Translucent shadows disappear after press Play button

Hi to all…

After a few days fighting with tulle curtains in my project I´ve almost finished with it. Now i have a new problem…The translucent shadows from the tulle curtains disappear when i press Play button. I have tried raising the resolution of the lightmaps both on the curtain and on the floor without any result. Also whe I activate Cast Volumetric Shadow the curtain is too bright and I don’t know how to avoid it…