# Malloc() error on Ubuntu
**URL:** https://community.freefem.org/t/malloc-error-on-ubuntu/634
**Category:** General Discussion
**Created:** [November 4, 2020, 10:13am UTC](https://community.freefem.org/t/malloc-error-on-ubuntu/634 "2020-11-04T10:13:58Z")
**Posts on this page:** 12
**Page:** 1
### Author:  [@Lily](https://community.freefem.org/u/Lily)
#### Post date: [November 4, 2020, 10:13am UTC](https://community.freefem.org/t/malloc-error-on-ubuntu/634/1 "2020-11-04T10:13:58Z")
Hello,
I’m using FreeFem on Ubuntu 20.04 and I have a strange issue.
I simply want to glue two meshes with the command “Th = Th1 + Th2”.
It returns the error
“malloc(): invalid size (unsorted)
Abandon (core dumped)”
I don’t understand why. The very same code runs properly on my Windows machine, so I guess it’s an Ubuntu issue…
Can anyone help me?!
Thanks a lot.
Lily
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### Author:  [@prj](https://community.freefem.org/u/prj)
#### Post date: [November 4, 2020, 1:29pm UTC](https://community.freefem.org/t/malloc-error-on-ubuntu/634/2 "2020-11-04T13:29:41Z")
Hello Lily,
Could you please share your code?
Thanks.
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### Author:  [@Lily](https://community.freefem.org/u/Lily)
#### Post date: [November 4, 2020, 1:55pm UTC](https://community.freefem.org/t/malloc-error-on-ubuntu/634/3 "2020-11-04T13:55:39Z")
Hello prj,
I have extracted the simplest code :
load “msh3”
mesh3 Th, Th1, Th2;
Th1 = readmesh3(“mesh1.mesh”);
Th2 = readmesh3(“mesh2.mesh”);
Th = Th1 + Th2;
savemesh(Th,“finalmesh.mesh”);
The meshes “mesh1.mesh” and “mesh2.mesh” were created with GMSH, then remeshed with MMG3D. They have respectively 30246 and 33342 tetrahedral elements.
Even with the simplest code above, I get the malloc error on Ubuntu and not on Windows. Otherwise, all my code run correctly on Ubuntu.
Thank you.
---
### Author:  [@prj](https://community.freefem.org/u/prj)
#### Post date: [November 4, 2020, 1:57pm UTC](https://community.freefem.org/t/malloc-error-on-ubuntu/634/4 "2020-11-04T13:57:47Z")
We need those meshes. Are they conforming?
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### Author:  [@Lily](https://community.freefem.org/u/Lily)
#### Post date: [November 4, 2020, 2:48pm UTC](https://community.freefem.org/t/malloc-error-on-ubuntu/634/5 "2020-11-04T14:48:43Z")
Yes, they are conforming.
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### Author:  [@prj](https://community.freefem.org/u/prj)
#### Post date: [November 4, 2020, 3:35pm UTC](https://community.freefem.org/t/malloc-error-on-ubuntu/634/6 "2020-11-04T15:35:18Z")
Upload them somewhere so we can reproduce the error, please.
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### Author:  [@prj](https://community.freefem.org/u/prj)
#### Post date: [November 4, 2020, 8:12pm UTC](https://community.freefem.org/t/malloc-error-on-ubuntu/634/8 "2020-11-04T20:12:21Z")
What is your FreeFEM version?
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### Author:  [@Lily](https://community.freefem.org/u/Lily)
#### Post date: [November 5, 2020, 7:14am UTC](https://community.freefem.org/t/malloc-error-on-ubuntu/634/9 "2020-11-05T07:14:47Z")
I’m using FreeFem++ 4.1
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### Author:  [@prj](https://community.freefem.org/u/prj)
#### Post date: [November 5, 2020, 7:28am UTC](https://community.freefem.org/t/malloc-error-on-ubuntu/634/10 "2020-11-05T07:28:49Z")
Please update to the latest version, 4.7-1, there is no error there.
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### Author:  [@Lily](https://community.freefem.org/u/Lily)
#### Post date: [November 5, 2020, 8:02am UTC](https://community.freefem.org/t/malloc-error-on-ubuntu/634/11 "2020-11-05T08:02:26Z")
Ok, I will. Is there a way to have both versions on the same machine, or do I have to uninstall the version 4.1 and then install the version 4.7-1?
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### Author:  [@prj](https://community.freefem.org/u/prj)
#### Post date: [November 5, 2020, 8:11am UTC](https://community.freefem.org/t/malloc-error-on-ubuntu/634/12 "2020-11-05T08:11:56Z")
If you compile FreeFEM from sources, you can have two installations. Otherwise, I’m not sure.
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### Author:  [@Lily](https://community.freefem.org/u/Lily)
#### Post date: [November 5, 2020, 10:13am UTC](https://community.freefem.org/t/malloc-error-on-ubuntu/634/13 "2020-11-05T10:13:23Z")
There is no error with the version 4.7-1.
Thank you!