# Error in LDLt decomposition

**URL:** <https://forum.spis.org/t/error-in-ldlt-decomposition/973>\
**Category:** SPIS\
**Created:** [10 March 2022 13:31 UTC](https://forum.spis.org/t/error-in-ldlt-decomposition/973 "2022-03-10T13:31:09Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Yago](https://forum.spis.org/letter_avatar_proxy/v4/letter/y/bc8723/32.png) [@Yago](https://forum.spis.org/u/Yago)\
**Post date:** [10 March 2022 13:31 UTC](https://forum.spis.org/t/error-in-ldlt-decomposition/973/1 "2022-03-10T13:31:10Z")

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Hello comunity,  
I have started a simulation with a simple geometry defined by an ellipsoid and inside it a cube with a square in on of its faces corresponding to the thruster. The mesh is defined as following:  
Mesh size at the ellipsoide: 10;  
Mesh size at the surface of the cube: 2;  
Mesh size at the thruster:1;  
When the simulation starts, an error pop up defined as following:  
error in LDLt decomposition in assembPrecontNonLinear=7.  
Does anybody know what can be the source of this error?  
Thank you very much,  
Yago

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**Author:** ![sebhess](https://forum.spis.org/letter_avatar_proxy/v4/letter/s/45deac/32.png) [@sebhess](https://forum.spis.org/u/sebhess)\
**Post date:** [27 June 2022 09:43 UTC](https://forum.spis.org/t/error-in-ldlt-decomposition/973/2 "2022-06-27T09:43:50Z")

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Hello Yago,  
did you check the mesh quality