# Contact and Mesh errors

**URL:** <https://prepomax.discourse.group/t/contact-and-mesh-errors/2743>\
**Category:** General Questions\
**Created:** [May 30, 2025, 5:44pm UTC](https://prepomax.discourse.group/t/contact-and-mesh-errors/2743 "2025-05-30T17:44:07Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Ruslan](https://avatars.discourse-cdn.com/v4/letter/r/2bfe46/32.png) [@Ruslan](https://prepomax.discourse.group/u/Ruslan)\
**Post date:** [May 30, 2025, 5:44pm UTC](https://prepomax.discourse.group/t/contact-and-mesh-errors/2743/1 "2025-05-30T17:44:07Z")

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I’m having trouble with a PrePoMax v2.2.0. I’m applying a 105 kN load on the groove, with the bottom fixed. I set a 2 mm contact tolerance and turned on “Adjust — Yes” for contacts, but I’m still getting errors:

“Opposite master face found but too far away” and “no tied MPC generated for node” (contact issues).

“Nonpositive Jacobian determinant in element” (mesh issues).

I tried fixing it by:

Making the mesh smaller (3 mm, ~2,7 million elements).

 ![Screenshot_2025-05-30-11-30-39-57_92460851df6f172a4592fca41cc2d2e6](https://global.discourse-cdn.com/free1/uploads/prepomax/original/2X/8/858fbd30cb5a6dc39f49c1c6bb0f9bc904409de6.jpeg)

Increasing tolerance to 5 mm.

Simplifying the model and adjusting solver settings (smaller time steps).

None of this worked, even after following earlier advice. Any ideas on how to fix the contact and mesh errors? Thanks.

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<div class="post-metadata">

**Author:** ![FEAnalyst](https://yyz2.discourse-cdn.com/free1/user_avatar/prepomax.discourse.group/feanalyst/32/688_2.png) [@FEAnalyst](https://prepomax.discourse.group/u/FEAnalyst)\
**Post date:** [May 30, 2025, 6:15pm UTC](https://prepomax.discourse.group/t/contact-and-mesh-errors/2743/2 "2025-05-30T18:15:07Z")

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> [@Ruslan](#):
>
> “Opposite master face found but too far away” and “no tied MPC generated for node” (contact issues).

If you measure the distance between the surfaces, how far are they from each other ?

> [@Ruslan](#):
>
> “Nonpositive Jacobian determinant in element” (mesh issues).

It’s often caused by adjustment in tie constraints.

> [@Ruslan](#):
>
> ~2,7 billion elements

Billion ?

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<div class="post-metadata">

**Author:** ![Ruslan](https://avatars.discourse-cdn.com/v4/letter/r/2bfe46/32.png) [@Ruslan](https://prepomax.discourse.group/u/Ruslan)\
**Post date:** [May 30, 2025, 10:32pm UTC](https://prepomax.discourse.group/t/contact-and-mesh-errors/2743/3 "2025-05-30T22:32:37Z")

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Corrected the post. Added a log.

 ![IMG_20250530_112936](https://global.discourse-cdn.com/free1/uploads/prepomax/original/2X/b/b4982c35740b92df2ee00bbd5fff184ea67eb0a1.jpeg)