sorry about all the threads! (armor stands)

[froggotheadmin]

i cannot place armor stands, nor can i summon them. I can share world files if necessary  

[NiLSPACE]

Those haven't been implemented either

In general, if something isn't working as expected, you can assume that it hasn't been (fully) implemented yet.

You can check out these links for a rough overview of what is implemented and what is missing:
https://github.com/cuberite/cuberite/issues/4888

https://forum.cuberite.org/thread-499.html