I'm trying to merge together two parts (the ones in the images) of a model using a boolean (union) modifier, but I get an error saying "Unable to execute boolean modifier". I browsed around a little but couldn't really find an answer which worked in my case, so I'm wondering how I can get the boolean modifier to work ~

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  • 2
    $\begingroup$ I'm guessing your model is non manifold. Also, edges directly placed on other edges will cause the boolean to fail in certain cases. you should make sure that this isn't causing any problems. Another thing: did you check if the normals are facing outwards? $\endgroup$
    – Delagone
    Jan 26, 2017 at 13:18
  • $\begingroup$ Are you able to post a .blend? $\endgroup$
    – fergal
    Jan 26, 2017 at 13:36

1 Answer 1


The problem was non-manifold geometry as mentioned in comments. After making mesh manifold Boolean modifier worked properly.


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