Incomplete experiments cannot be placed

it's caused by Geometric Placement. Holding Ctrl when you place to temporary disable that mod.

几何种植导致的，放置时按住Ctrl暂时禁用几何学

I'm not able to reproduce the issue.
Do you have any mods enabled? If so, could you please try again with all mods - including client-side mods - disabled?

Thank you.

Changed Status to Can't Reproduce