# Building error/bug

**URL:** https://discourse.stonehearth.net/t/building-error-bug/31521
**Category:** Bug Reports
**Tags:** building, a21r703
**Created:** [August 5, 2017, 1:47pm UTC](https://discourse.stonehearth.net/t/building-error-bug/31521 "2017-08-05T13:47:06Z")
**Posts on this page:** 1
**Page:** 1

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### Author: ![Niolop](https://sea2.discourse-cdn.com/flex022/user_avatar/discourse.stonehearth.net/niolop/32/55923_2.png) [@Niolop](https://discourse.stonehearth.net/u/Niolop)
#### Post date: [August 5, 2017, 1:47pm UTC](https://discourse.stonehearth.net/t/building-error-bug/31521/1 "2017-08-05T13:47:06Z")

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Hi there, as soon as I start building a bit more complicated, or otherwise custom buildings, at some point an error will appear. It’s mostly a random error. Sometimes the UI stops working, or I can’t save, or walls dissapear and whatnot.

I will provide the text I received last:

release-702 (x64)  
…onehearth/components/building/building\_component.lua:1158: attempt to index local ‘fab’ (a nil value)  
stack traceback:  
radiant/modules/common.lua:245: in function 'report\_traceback’  
radiant/modules/common.lua:256: in function \<radiant/modules/common.lua:250\>  
…onehearth/components/building/building\_component.lua:1158: in function ‘can\_scaffolding\_clear’  
…hearth/components/scaffolding/scaffolding\_region.lua:379: in function 'instance’  
radiant/modules/events.lua:291: in function \<radiant/modules/events.lua:285\>  
[C]: in function 'xpcall’  
radiant/modules/common.lua:265: in function 'xpcall’  
radiant/modules/events.lua:285: in function ‘trigger’  
…earth/components/fabricator/fabricator\_component.lua:254: in function 'fn’  
radiant/modules/events.lua:288: in function \<radiant/modules/events.lua:285\>  
[C]: in function ‘xpcall’  
…  
radiant/controllers/time\_tracker\_controller.lua:84: in function 'set\_now’  
radiant/controllers/time\_tracker\_controller.lua:124: in function 'increment\_now’  
radiant/modules/timer.lua:13: in function 'instance’  
radiant/modules/events.lua:291: in function \<radiant/modules/events.lua:285\>  
[C]: in function 'xpcall’  
radiant/modules/common.lua:265: in function 'xpcall’  
radiant/modules/events.lua:285: in function 'trigger’  
radiant/modules/events.lua:398: in function '\_trigger\_gameloop’  
radiant/modules/events.lua:446: in function '\_update’  
radiant/server.lua:61: in function \<radiant/server.lua:58\>

.  
The bug does not appear in pre-set buildings, such as a Dining hall or a tiny house.

Version of the game is Alpha 21