this is what I get…
release-549 (x32)
stonehearth/lib/build_util.lua:349: assertion failed!
stack traceback:
radiant/modules/common.lua:223: in function 'report_traceback’
radiant/modules/common.lua:234: in function <radiant/modules/common.lua:228>
[C]: in function 'assert’
stonehearth/lib/build_util.lua:349: in function ‘can_start_blueprint’
…earth/components/fabricator/fabricator_component.lua:727: in function ‘_start_project’
…earth/components/fabricator/fabricator_component.lua:530: in function ‘_updates_state’
…earth/components/fabricator/fabricator_component.lua:519: in function 'obj’
radiant/modules/events.lua:73: in function 'instance’
radiant/modules/events.lua:206: in function <radiant/modules/events.lua:200>
[C]: in function 'xpcall’
radiant/modules/common.lua:243: in function 'xpcall’
radiant/modules/events.lua:200: in function 'trigger’
radiant/modules/events.lua:269: in function '_trigger_gameloop’
radiant/modules/events.lua:320: in function '_update’
radiant/server.lua:62: in function <radiant/server.lua:58>
Welcome to the forum, @lucas_zarate 
Could you describe a little more? Did you get this error when you told to remove a design (still not built) ?
I had it too, was a while a played but im back in again! But when i had the problem i got a error message (Don’t know how it looked 
) but it happend every time i made a new game and wanted to delete a building that didn’t complete! Or that i was unsatisfied.
Note: The error message just came up once every game.
Hope this gave you some information.