# Umfpack64 can not work

**URL:** <https://community.freefem.org/t/umfpack64-can-not-work/1263>\
**Category:** General Discussion\
**Created:** [October 19, 2021, 2:40am UTC](https://community.freefem.org/t/umfpack64-can-not-work/1263 "2021-10-19T02:40:45Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![xiaojiemo](https://avatars.discourse-cdn.com/v4/letter/x/a4c791/32.png) [@xiaojiemo](https://community.freefem.org/u/xiaojiemo)\
**Post date:** [October 19, 2021, 2:40am UTC](https://community.freefem.org/t/umfpack64-can-not-work/1263/1 "2021-10-19T02:40:45Z")

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after loading, while it can not work. and the character “defaulttoUMFPACK64()” can not be identified.

 ![25ebb6dca1e485bc1e0fb2f3fbed51f](https://canada1.discourse-cdn.com/flex030/uploads/freefem/original/1X/c65742f93795f75fa37fda0f9173993710bbc996.png)

 ![536898206f8c32300c284402d72a7fd](https://canada1.discourse-cdn.com/flex030/uploads/freefem/original/1X/9a81665baea492247e6d75bb0dd0c18273207c0a.png)

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**Author:** ![frederichecht](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.freefem.org/frederichecht/32/15_2.png) [@frederichecht](https://community.freefem.org/u/frederichecht)\
**Post date:** [October 20, 2021, 9:11am UTC](https://community.freefem.org/t/umfpack64-can-not-work/1263/2 "2021-10-20T09:11:37Z")

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The word UMFPACK64 do not existe

use “UMFPACK64”

problem laplace(uh,vh,solver=“UMFPACK64”) = // Definion of the problem  
int2d(Th,qft=qf7pT)( dx(uh)\*dx(vh) + dy(uh)\*dy(vh) ) // bilinear form

- int2d(Th,qft=qf7pT)( f\*vh ) // linear form

- on(1,2,3,4,uh=g) ; // boundary condition form

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**Author:** ![xiaojiemo](https://avatars.discourse-cdn.com/v4/letter/x/a4c791/32.png) [@xiaojiemo](https://community.freefem.org/u/xiaojiemo)\
**Post date:** [October 22, 2021, 10:51am UTC](https://community.freefem.org/t/umfpack64-can-not-work/1263/3 "2021-10-22T10:51:32Z")

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Thanks for your advice.