Code:
var bodentiles[4000];

array indices 0-3999?
Code:
while (i < 4001) 
{
   bodentiles[i] = 0;
   i += 1;
}

array bounds exceeded?
Quoting xXReapeRXx.
Quote:
180000 Fog of War entities.. only for fow...

1. Maybe only space d / area a is visible at time t, thus, perhaps, only max n entities are required to cover visible d / a.
2. A separate function / loop / action might not be required for each coverage entity, where only one loop might do.
3. Potentially separate from visible coverage entities, cell visible states might only require boolean slots (vs var long = memory savings?).