I tried Blueprint 0019 and 0020 on one of my ongoing LDD projects.
They both crashed with a "null!!!" message out of nowhere, but loading and saving again in LDD misteriously solved the issue on the 0020:
Rendering assembly x10
Centering viewport 1.0443491,0.30602288
Rendering assembly x20
null!!!
Exception in thread "JavaFX Application Thread" java.lang.RuntimeException: java
.lang.RuntimeException: java.lang.RuntimeException: java.lang.NullPointerException
at blueprint.Blueprint.h(Unknown Source)
at com.sun.javafx.application.PlatformImpl.lambda$null$173(PlatformImpl.java:295)
[...]
I also got lots of "Bounding box overflow" when (re)generating:
Rendering assembly x180
Centering viewport 0.32566673,-0.5251057
Bounding box overflow
Rendering assembly x190
Centering viewport 0.32566673,-0.5251057
Bounding box overflow
[...]
Here are a few quick suggestions for possible future releases.
Pieces should not be placed in mid-air.
Some parts should be grouped by default (torso assemblies, train motors... once loaded and parsed the LXF file if you scan the parts list for a "torso" probably there are "hands" parts as well, within reasonable radius).
Doors and windows including a glass should be in the same step of the glass (it was funny having those door glasses stuck in mid-air for a number of pages because I forgot to manually move them before regenerating).
It would be nice to have an option to add below the left pane a text list of the same pieces (something like: "1x ROOF TILE 1X2X3/74° INV, Bright Yellow").
It is difficult to spot parts less than some 30-40% visible; it would be nice to have some option to require the user to rotate the view or modify the step if visibility is below some threshold (maybe some thin guidelines on the x and y axes could be easier to implement). I had a hard time figuring where the heck that black 2x6 plate was intended for... and it was on the train wheels bearing element, hidden by the chassis.