Game crashing when you put signs

When you put signs the game crash

What I expected to happen was...:
I expected that the sign will be plased normaly like the others

What actually happened was...:
I whas plasing signs and firs it work normaly but when i put some more signs the game crach. (This hapends every time i put many signs)

Steps to Reproduce:
1. Put some signs
2. If every thing is whorking put more signs
3. the game Will crach!