These are a few reasons for the dreaded bug of. Map crashing

!
- You used Special Mode in X-tra editor.
- Stacked a lot of buildings (Besides it looks noobish that way)
- You used starforge for stacking building and some sprites that make it crash
.
Those are things that you should never do.
These are things that you should do!
- Use Base Mode in X-tra editor. It looks a lot more neat and less newbish

- Use starforge for terrain only?
Yoshi has more but I think I covered it mostly! w00t , hope this helps you!