glass disappearing

[Prosciutto]

i made a map with glass on the middle point. but when i look in a specific place at the glass it disappears but i can't shoot the barrels behind it so basically it's invisible. it happends with every glass texture. how do i fix this

 

[Tumby]

Can you provide some images? What does the setup look like, where does it get invisible and so on.

 

[Viemärirotta]

It could be the glass shows unactivated visleaves, but providing screenshots is good for a start.

 

[Prosciutto]

oh i already fixed it. all i had to do is change the lighting