# Error with FreeFem

**URL:** <https://community.freefem.org/t/error-with-freefem/685>\
**Category:** FreeFEM installation\
**Created:** [December 13, 2020, 2:30am UTC](https://community.freefem.org/t/error-with-freefem/685 "2020-12-13T02:30:44Z")\
**Posts on this page:** 4\
**Page:** 1

<div class="post-metadata">

**Author:** ![Emma87](https://avatars.discourse-cdn.com/v4/letter/e/e47774/32.png) [@Emma87](https://community.freefem.org/u/Emma87)\
**Post date:** [December 13, 2020, 2:30am UTC](https://community.freefem.org/t/error-with-freefem/685/1 "2020-12-13T02:30:44Z")

</div>

The ff-mpirun and FreeFem ++ command is not being recognized after finishing the installation of the latest version of FreeFem on my Ubuntu 20.04LTS machine[config.log](https://community.freefem.org/uploads/short-url/6Vh18GDtmscJD5zRWmU5qjCCuv3.log) (339.7 KB)

---

<div class="post-metadata">

**Author:** ![prj](https://avatars.discourse-cdn.com/v4/letter/p/ecae2f/32.png) [@prj](https://community.freefem.org/u/prj)\
**Post date:** [December 13, 2020, 8:37am UTC](https://community.freefem.org/t/error-with-freefem/685/2 "2020-12-13T08:37:55Z")

</div>

You are using a prefix install, so you need to make sure those binaries are in your path.

```auto
export PATH=${PATH}:/home/hpc/FreeFem-install/bin

```

Also, for good measures, you may need to adjust the appropriate include and load paths as follows in `${HOME}/.freefem++.pref`.

```auto
loadpath += "/home/hpc/FreeFem-install/path_of_all.so"
includepath += "/home/hpc/FreeFem-install/path_of_all.idp"

```

I don’t use `make install`, so I can’t give you the exact path, but it should be something along `lib/ff++/4.7-1/plugin` and `lib/ff++/4.7-1/idp` (maybe? to be checked on your machine).

---

<div class="post-metadata">

**Author:** ![Emma87](https://avatars.discourse-cdn.com/v4/letter/e/e47774/32.png) [@Emma87](https://community.freefem.org/u/Emma87)\
**Post date:** [December 13, 2020, 3:03pm UTC](https://community.freefem.org/t/error-with-freefem/685/3 "2020-12-13T15:03:56Z")

</div>

Thanks prj, It now works well, just a query when I try to print the matrix with the command:  
ff-mpirun -np 2 matrix.edp -v 0 -mat\_view draw -draw\_pause -1  
it does not work

---

<div class="post-metadata">

**Author:** ![prj](https://avatars.discourse-cdn.com/v4/letter/p/ecae2f/32.png) [@prj](https://community.freefem.org/u/prj)\
**Post date:** [December 13, 2020, 3:28pm UTC](https://community.freefem.org/t/error-with-freefem/685/4 "2020-12-13T15:28:37Z")

</div>

Probably because your PETSc is compiled with `--with-x=0` (flag put by default if you use `make petsc-slepc`).  
To make sure, you can do the following.

```auto
$ cat flags.edp
load "PETSc"
$ ff-mpirun flags.edp -log_view | grep "Configure options"
// check for --with-x=0 in the output

```