Problem with light

[diable122]

Hi (sory for my english because I lerning it)
so i have problem with light

How you can see if i light front of me the light shines but if i look back something like this happens

Somebody can tell me what is wrong with it? i have this on all projects.
Cubes and all game objects are normal just terrain do this problem
thank you in advance for your help (agains sorry for spellings)

[diable122]

Oh I know what is wrong! when I add texture, I put one in first frame and one in second frame and then this problem is but when i put just in first frame everything is good also thanks for all.