Dear Xinling,

One of our partner reported a crash report in connection with changing the height of the model reference plane.
Here you can find the steps: https://drive.google.com/drive/folders/1kakxSAUhTusfTMweK6lapPx_ARyoAe8h?usp=share_link
Allplan version: 2022-1-9.
This crash can be repeated by using a simple box object as well, this modell is not needed for it.
If you need this specific modell, than I can send you in a private message.

Regards,
Balázs