# Engine Error in Building

**URL:** <https://discourse.stonehearth.net/t/engine-error-in-building/22323>\
**Category:** Previous Build Reports\
**Created:** [May 22, 2016, 8:01pm UTC](https://discourse.stonehearth.net/t/engine-error-in-building/22323 "2016-05-22T20:01:13Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![zedie](https://avatars.discourse-cdn.com/v4/letter/z/6bbea6/32.png) [@zedie](https://discourse.stonehearth.net/u/zedie)\
**Post date:** [May 22, 2016, 8:01pm UTC](https://discourse.stonehearth.net/t/engine-error-in-building/22323/1 "2016-05-22T20:01:13Z")

</div>

So I was building a wonderful two story house. With slab stairs, and then as I placed a door to finish it off I realized I placed a reinforced door. So I grabbed the eraser tool and erased the door. I replaced it with a regular door and clicked build. the workers didn’t do anything and an engine error popped up.

**Steps to reproduce:**

1. Build house
2. Add reinforced door, then click build. Pause building and replace with regular door.  
3)Enjoy Engine error

**Expected Results:**  
The workers should build my house  
**Actual Results:**  
They don’t touch the house, and the error comes up.  
**Notes:**  
release-553 (x64)  
…h/components/entity\_forms/entity\_forms\_component.lua:359: assertion failed!  
stack traceback:  
[C]: ?  
[C]: in function ‘assert’  
…h/components/entity\_forms/entity\_forms\_component.lua:359: in function ‘place\_item\_on\_structure’  
…/fixture\_fabricator/fixture\_fabricator\_component.lua:266: in function ‘\_place\_item\_on\_structure’  
…/fixture\_fabricator/fixture\_fabricator\_component.lua:243: in function ‘\_place\_fixture’  
…/fixture\_fabricator/fixture\_fabricator\_component.lua:203: in function ‘\_start\_project’  
…/fixture\_fabricator/fixture\_fabricator\_component.lua:41: in function \<…/fixture\_fabricator/fixture\_fabricator\_component.lua:39\>  
**Attachments:**  
I’m not sure what to put here.  
**Version Number and Mods in use:**  
Most recent. A16 I think.

**System Information:**  
Ummmmm, I’m not terribly techy. Gateway laptop?

---

<div class="post-metadata">

**Author:** ![Geokhan](https://sea2.discourse-cdn.com/flex022/user_avatar/discourse.stonehearth.net/geokhan/32/50159_2.png) [@Geokhan](https://discourse.stonehearth.net/u/Geokhan)\
**Post date:** [May 22, 2016, 10:39pm UTC](https://discourse.stonehearth.net/t/engine-error-in-building/22323/2 "2016-05-22T22:39:59Z")

</div>

Hello @zedie

to answer some of the questions in your post.

-attachments would include: save game file, stonehearth.log file, screenshots, templates.

-Version number is: release 553 as displayed in your error message.

I have had building mess up due to trying to change them after I hit build. Including your stonehearth.log file, which is located in your stonehearth folder may provide additional clues as to what process threw this error after the change.

reporting your information here may also be useful.

[http://discourse.stonehearth.net/t/a16-the-buildings-my-hearthlings-will-not-build-round-2/22200](http://discourse.stonehearth.net/t/a16-the-buildings-my-hearthlings-will-not-build-round-2/22200)