# Trouble using Pardiso for Ipopt with Windows Operating System

**URL:** <https://discourse.julialang.org/t/trouble-using-pardiso-for-ipopt-with-windows-operating-system/17221>\
**Category:** New to Julia\
**Tags:** question, optimization\
**Created:** [November 6, 2018, 8:21pm UTC](https://discourse.julialang.org/t/trouble-using-pardiso-for-ipopt-with-windows-operating-system/17221 "2018-11-06T20:21:40Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![astor87](https://avatars.discourse-cdn.com/v4/letter/a/f14d63/32.png) [@astor87](https://discourse.julialang.org/u/astor87)\
**Post date:** [November 6, 2018, 8:21pm UTC](https://discourse.julialang.org/t/trouble-using-pardiso-for-ipopt-with-windows-operating-system/17221/1 "2018-11-06T20:21:40Z")

</div>

I am struggling to use the linear algebra library Pardiso with Ipopt in Julia with JuMP. I have a very large nonlinear problem and it is my understanding that Pardiso may be more efficient and speed up the iterations. I have been trying to follow along with the discussion here:

[https://github.com/JuliaOpt/Ipopt.jl/issues/83](https://github.com/JuliaOpt/Ipopt.jl/issues/83)

which seems to be using Pardiso without doing a custom build of Ipopt. I am currently solving problems using the MUMPS library.

My system:  
-Windows 10 64-bit operating system, 16 GB RAM  
-Julia v0.6.4  
-JuMP v0.18.2  
-Pardiso v6

What I have done:  
(1) Install Pardiso.jl (Pkg.add(“Pardiso”) )

> julia\> Pkg.add(“Pardiso”)  
> INFO: Cloning cache of Pardiso from [GitHub - JuliaSparse/Pardiso.jl: Calling the PARDISO library from Julia](https://github.com/JuliaSparse/Pardiso.jl.git)  
> INFO: Installing Pardiso v0.3.2  
> INFO: Building Pardiso  
> did not find libpardiso, assuming PARDISO 5.0 is not installed  
> did not find MKLROOT key, assuming MKL is not installed  
> WARNING: no Pardiso library managed to load  
> INFO: Package database updated  
> INFO: METADATA is out-of-date — you may not have the latest version of Pardiso  
> INFO: Use `Pkg.update()` to get the latest versions of your packages

(2) Download `libpardiso600-WIN-X86-64.dll` and put this and the `pardiso.lic` in `Pkg.dir("WinRPM", "deps", "usr", "x86_64-w64-mingw32", "sys-root", "mingw", "bin")`. I also renamed copies of `libpardiso600-WIN-X86-64.dll` as `libpardiso.dll` and `libpardiso.so` in this folder.  
(3) Pkg.build(“Pardiso”)

> Pkg.build(“Pardiso”)  
> INFO: Building Pardiso  
> did not find libpardiso, assuming PARDISO 5.0 is not installed  
> did not find MKLROOT key, assuming MKL is not installed  
> WARNING: no Pardiso library managed to load

(4) When I run the julia code with `m=Model(solver = IpoptSolver(linear\_solver=“pardiso”))', I get:

> EXIT: Invalid option encountered.  
> WARNING: Ipopt finished with status Invalid\_Option  
> WARNING: Not solved to optimality, status: Error  
> Objective Value: 0.0  
> Exception of type: OPTION\_INVALID in file “IpAlgBuilder.cpp” at line 366:  
> Exception message: Selected linear solver Pardiso not available.  
> Tried to obtain Pardiso from shared library “libpardiso.dll”, but the following error occured:  
> Windows error while loading dynamic library libpardiso.dll, error = 126.  
> (see [Tutorial - Debug system error codes - Win32 apps | Microsoft Learn](http://msdn.microsoft.com/en-us/library/ms681381%28v=vs.85%29.aspx))

Any help would be appreciated!

---

<div class="post-metadata">

**Author:** ![kristoffer.carlsson](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/kristoffer.carlsson/32/22_2.png) [@kristoffer.carlsson](https://discourse.julialang.org/u/kristoffer.carlsson)\
**Post date:** [November 6, 2018, 8:28pm UTC](https://discourse.julialang.org/t/trouble-using-pardiso-for-ipopt-with-windows-operating-system/17221/2 "2018-11-06T20:28:24Z")

</div>

`WARNING: no Pardiso library managed to load` is a bad sign.

What happens if you put `libpardiso600-WIN-X86-64.dll` into `.julia/0.6/Pardiso/deps`?

---

<div class="post-metadata">

**Author:** ![astor87](https://avatars.discourse-cdn.com/v4/letter/a/f14d63/32.png) [@astor87](https://discourse.julialang.org/u/astor87)\
**Post date:** [November 7, 2018, 2:52am UTC](https://discourse.julialang.org/t/trouble-using-pardiso-for-ipopt-with-windows-operating-system/17221/3 "2018-11-07T02:52:44Z")

</div>

I put `libpardiso600-WIN-X86-64.dll` into `C:\JuliaPro-0.6.4.1\pkgs-0.6.4.1\v0.6\Pardiso\deps` and did `Pkg.build("Pardiso")` and got the same result:

> julia\> Pkg.build(“Pardiso”)  
> INFO: Building Pardiso  
> did not find libpardiso, assuming PARDISO 5.0 is not installed  
> did not find MKLROOT key, assuming MKL is not installed  
> WARNING: no Pardiso library managed to load

I then tried running my julia code with ipopt solver using Pardiso and I got the same message as before.