Remember, the build time of all ships have been reduced to 1/10. I finally figured out that the build time of any ship must be longer than 1.0 second. I found the build time of defender, probe and proximity sensor was set to 0.6, so that caused the problem confusing me for quite a while. Now it's figured out and totally sovled, 0.6 is changed to 2.0, and the game won't crash any more! Now I can enjoy it, you too!
No problem anymore!
