The building design bug

Summary:
The slab will become invisible and can not be removed,also u cant build anything coz the block is actually here
The worker cant aslo do anything to it but they can walk on it like walking on the air

Steps to reproduce:
1)Create some slab in a house
2) After the workers built the slab “you can actually see it”, use the slab erase function on the built slab
3)save and load your game
4)Go and check the slab you erased you will mention that they disappered
5)now you have some invisible slab they the worker can do nothing on it (except walking on it)
You cant even build slabs on the place

Expected Results:
Idk what should it be if i erase the built slab

Actual Results:
You got some bugged slab

Notes:
""""""""""""“A error appear every time i load the game”"""""""""""
release-523 (x64)
…onehearth/components/building/building_component.lua:295: attempt to index local ‘entity’ (a nil value)
stack traceback:
radiant/modules/common.lua:214: in function 'report_traceback’
radiant/modules/common.lua:225: in function <radiant/modules/common.lua:219>
…onehearth/components/building/building_component.lua:295: in function ‘_trace_entity’
…onehearth/components/building/building_component.lua:105: in function ‘_restore_structure_traces’
…onehearth/components/building/building_component.lua:66: in function 'obj’
radiant/modules/events.lua:76: in function 'instance’
radiant/modules/events.lua:209: in function <radiant/modules/events.lua:203>
[C]: in function 'xpcall’
radiant/modules/common.lua:234: in function 'xpcall’
radiant/modules/events.lua:203: in function <radiant/modules/events.lua:174>
Attachments:

Version Number and Mods in use:
Version release 523 and no mods using

System Information:
Win 7 64bit
8gb ram
GTX970 display

Sorry for my poor english and bad presentation

A post was merged into an existing topic: Error in building component - restore structure traces