I think every scenery designer will know how to do this. Just do something slightly wrong in your addon BGL file and FS will clearly tell you it does not like your new file. Especially when you start to tweak the ASM or SCASM source codes manual it is very easy to do something wrong.

But while working on MDL Tweaker II last evening I was able to make it crash even better. As you might know MDL Tweaker II does edit the MDL files directly, so I am writing the binary code to it directly. And while testing the feature to add conditions I by accident made a jump that jumped ahead 0 bytes. So it would jump to itself, and then jump again to itself, and then… Well I guess you can guess where this ends. FS clearly did not like this new MDL file (although BGLComp did not complain during compilation). Once I fired up Fs2004 the loading screen showed up for a little while and then I was back at my desktop, without any error or warning.

Now I understand a bit better why MS does not very actively encourage this kind of object tweaking. The chances that you make an error are quite large and their support will not appreciate problems like this as well. But that is no problem for me, I have already accepted that most of the crashes I get here are caused by myself. That is just the price you have to pay, when you try to extend the use of your scenery.