# Error: operation failed as the resulting body would be invalid

**URL:** <https://discourse.shapr3d.com/t/error-operation-failed-as-the-resulting-body-would-be-invalid/27894>\
**Category:** Modeling Questions\
**Created:** [September 13, 2023, 11:33am UTC](https://discourse.shapr3d.com/t/error-operation-failed-as-the-resulting-body-would-be-invalid/27894 "2023-09-13T11:33:02Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![Aparna28](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.shapr3d.com/aparna28/32/22401_2.png) [@Aparna28](https://discourse.shapr3d.com/u/Aparna28)\
**Post date:** [September 13, 2023, 11:33am UTC](https://discourse.shapr3d.com/t/error-operation-failed-as-the-resulting-body-would-be-invalid/27894/1 "2023-09-13T11:33:02Z")

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I’m trying to loft 5 ellipses that are drawn on different planes. ( img1) I’ve drawn guidelines too. But when I try to loft, the resulting body emerges ( img2) but when I select the guide rails to define the curves of the loft I get the alert (img 3) Because of that I’m not able to get the curved shape I desire. What is going wrong? [IMG\_0501|689x481](https://discourse.shapr3d.com/uploads/short-url/nEKb6W2dtCI4aEv0elDP6AZz6ey.jpeg)

 ![IMG_0502](https://us1.discourse-cdn.com/flex002/uploads/shapr3d/original/3X/2/d/2da7d0c04b5eee1fcc5a5a72b246a9c99bab6e57.jpeg)  
 ![IMG_0500](https://us1.discourse-cdn.com/flex002/uploads/shapr3d/original/3X/a/9/a9a921d34bb8a0726f624ed030f5d84f05e487f9.jpeg)  
 ![IMG_0503](https://us1.discourse-cdn.com/flex002/uploads/shapr3d/original/3X/3/0/30bb7331670aa25a210858fc33691e57b765e5b4.jpeg)

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**Author:** ![Laci\_K](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.shapr3d.com/laci_k/32/8196_2.png) [@Laci\_K](https://discourse.shapr3d.com/u/Laci_K)\
**Post date:** [September 13, 2023, 12:01pm UTC](https://discourse.shapr3d.com/t/error-operation-failed-as-the-resulting-body-would-be-invalid/27894/2 "2023-09-13T12:01:08Z")

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Hi,

Guide lines need to connect to the profiles you want to use for loft. From your third image, it seems like they are either not touching, or inside the filling, both cases make it impossible to use them as guides.

I suggest using Fit point splines, and connecting them to the profiles. You will see purple dots where they can connect.

 ![image](https://us1.discourse-cdn.com/flex002/uploads/shapr3d/original/3X/7/e/7e5ca9b123e8a45a7f024ede4848f2204f335097.png)  
 ![image](https://us1.discourse-cdn.com/flex002/uploads/shapr3d/original/3X/5/2/52154217b84b947384b603cec968fd2ee74f2f2f.png)

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**Author:** ![Stephen](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.shapr3d.com/stephen/32/16350_2.png) [@Stephen](https://discourse.shapr3d.com/u/Stephen)\
**Post date:** [September 13, 2023, 6:10pm UTC](https://discourse.shapr3d.com/t/error-operation-failed-as-the-resulting-body-would-be-invalid/27894/3 "2023-09-13T18:10:07Z")

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As Laci suggested, Fit Splines are better for this. Much faster and easier to connect to points.  
This rough example only took me a couple of minutes to make using Fit Splines

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<div class="post-metadata">

**Author:** ![Aparna28](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.shapr3d.com/aparna28/32/22401_2.png) [@Aparna28](https://discourse.shapr3d.com/u/Aparna28)\
**Post date:** [September 13, 2023, 7:08pm UTC](https://discourse.shapr3d.com/t/error-operation-failed-as-the-resulting-body-would-be-invalid/27894/4 "2023-09-13T19:08:05Z")

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Thank you laci 🙂 I was using control spline all this while… that caused the issue!