Cannot design designer building using building design tool

Designing buildings cannot take place as it will not allow the placement of objects or major parts of the building, eg: walls, roof.

Steps to reproduce:

  1. Click on building designer tool
  2. Attempt to place item

Expected Results:
For the item in question to appear where placed.
Actual Results:
Does not appear and resets the item back into the list
Notes:
Was working before latest small update cubemitter optimizations.
Attachments:

Version Number and Mods in use:
Alpha 20
System Information:
windows 10 x64

I have just noticed that that a previous world created before the cubemitter optimization doesn’t contain the bug.

Sorry for the late reply, @Zappica, and belated welcome to the forum.

Do you have the savefile where this was happening?

It might be the case that you’re trying to place something in a place where it’s not allowed.
Have you re-encountered this bug since then?