The limited number of objects in the Lite version is announced in the description on the AppStore.
In older version, the limit was 12 objects.
But perhaps that it will be better if an alert prevents the user when the limit is exceeded.
The current drawing is saved when you go to the screen "Files" and so before you can send it.
If you don't see the objects on the screen, try a 4x taps on the screen to do a zoom all objects.
If you buy the full version, you can transfer your file but with 50 objects only.
Between the Lite version and the full version, it is the same code, so same bugs too.
If you can reproduce a crash step by step, I can probably fix it if you explain to me how do it.
2D CAD software for iPhone and iPad