# Boolean fail when subtracting shapes
**URL:** https://discourse.shapr3d.com/t/boolean-fail-when-subtracting-shapes/3616
**Category:** Modeling Questions
**Created:** [December 27, 2018, 6:50pm UTC](https://discourse.shapr3d.com/t/boolean-fail-when-subtracting-shapes/3616 "2018-12-27T18:50:40Z")
**Posts on this page:** 8
**Page:** 1
### Author:  [@WayneC](https://discourse.shapr3d.com/u/WayneC)
#### Post date: [December 27, 2018, 6:50pm UTC](https://discourse.shapr3d.com/t/boolean-fail-when-subtracting-shapes/3616/1 "2018-12-27T18:50:40Z")
When attempting to “subtract” one part from another of a fairly simple shape, I get the boolean error message
Can you tell me why?
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### Author:  [@WayneC](https://discourse.shapr3d.com/u/WayneC)
#### Post date: [December 27, 2018, 6:53pm UTC](https://discourse.shapr3d.com/t/boolean-fail-when-subtracting-shapes/3616/3 "2018-12-27T18:53:27Z")
done thanks
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### Author:  [@WayneC](https://discourse.shapr3d.com/u/WayneC)
#### Post date: [December 27, 2018, 6:53pm UTC](https://discourse.shapr3d.com/t/boolean-fail-when-subtracting-shapes/3616/4 "2018-12-27T18:53:50Z")
attempting to subtract the darker shape from the lighter one
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### Author:  [@WayneC](https://discourse.shapr3d.com/u/WayneC)
#### Post date: [December 27, 2018, 7:01pm UTC](https://discourse.shapr3d.com/t/boolean-fail-when-subtracting-shapes/3616/6 "2018-12-27T19:01:16Z")
yes correct
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### Author:  [@WayneC](https://discourse.shapr3d.com/u/WayneC)
#### Post date: [December 27, 2018, 7:02pm UTC](https://discourse.shapr3d.com/t/boolean-fail-when-subtracting-shapes/3616/8 "2018-12-27T19:02:54Z")
yes post it here?
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### Author:  [@WayneC](https://discourse.shapr3d.com/u/WayneC)
#### Post date: [December 27, 2018, 7:07pm UTC](https://discourse.shapr3d.com/t/boolean-fail-when-subtracting-shapes/3616/10 "2018-12-27T19:07:40Z")
[snap on slide.shapr](https://us1.discourse-cdn.com/flex002/uploads/shapr3d/original/2X/2/2b7175150cd0705becf40959cc8102005c6c65ec.shapr) (1.3 MB)
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### Author:  [@WayneC](https://discourse.shapr3d.com/u/WayneC)
#### Post date: [December 27, 2018, 7:57pm UTC](https://discourse.shapr3d.com/t/boolean-fail-when-subtracting-shapes/3616/14 "2018-12-27T19:57:05Z")
got it thanks!
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### Author:  [@DanielR](https://discourse.shapr3d.com/u/DanielR)
#### Post date: [December 28, 2018, 12:43am UTC](https://discourse.shapr3d.com/t/boolean-fail-when-subtracting-shapes/3616/16 "2018-12-28T00:43:58Z")
Hi - I’ve created a ticket for the devs to see what the problem could be. The issue is with the white body, it behaves as a non-manifold body, but not all the time (like you can extrude a closed sketch and union them, but can’t union a new extrusion with push-pull) - it’s a weird behaviour that came up recently with another user, we will look into it.