# ReadOnlyMemoryError using Ipopt not fixed in 0.51

**URL:** <https://discourse.julialang.org/t/readonlymemoryerror-using-ipopt-not-fixed-in-0-51/2611>\
**Category:** Optimization (Mathematical)\
**Created:** [March 11, 2017, 8:50pm UTC](https://discourse.julialang.org/t/readonlymemoryerror-using-ipopt-not-fixed-in-0-51/2611 "2017-03-11T20:50:33Z")\
**Posts on this page:** 9\
**Page:** 1

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**Author:** ![Frank\_Kampas](https://avatars.discourse-cdn.com/v4/letter/f/a183cd/32.png) [@Frank\_Kampas](https://discourse.julialang.org/u/Frank_Kampas)\
**Post date:** [March 11, 2017, 8:50pm UTC](https://discourse.julialang.org/t/readonlymemoryerror-using-ipopt-not-fixed-in-0-51/2611/1 "2017-03-11T20:50:33Z")

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ReadOnlyMemoryError()

in solveProblem(::Ipopt.IpoptProblem) at C:\Users\Frank.julia\v0.5\Ipopt\src\Ipopt.jl:304  
in optimize!(::Ipopt.IpoptMathProgModel) at C:\Users\Frank.julia\v0.5\Ipopt\src\IpoptSolverInterface.jl:120  
in #solvenlp#150(::Bool, ::Function, ::JuMP.Model, ::JuMP.ProblemTraits) at C:\Users\Frank.julia\v0.5\JuMP\src\nlp.jl:1208  
in (::JuMP.#kw##solvenlp)(::Array{Any,1}, ::JuMP.#solvenlp, ::JuMP.Model, ::JuMP.ProblemTraits) at .\<missing\>:0  
in #solve#97(::Bool, ::Bool, ::Bool, ::Array{Any,1}, ::Function, ::JuMP.Model) at C:\Users\Frank.julia\v0.5\JuMP\src\solvers.jl:139  
in packcircles(::Array{Int64,1}, ::Int64) at .\In[6]:36

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**Author:** ![miles.lubin](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/miles.lubin/32/279_2.png) [@miles.lubin](https://discourse.julialang.org/u/miles.lubin)\
**Post date:** [March 13, 2017, 9:16pm UTC](https://discourse.julialang.org/t/readonlymemoryerror-using-ipopt-not-fixed-in-0-51/2611/2 "2017-03-13T21:16:10Z")

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See discussion at [https://github.com/JuliaOpt/Ipopt.jl/issues/81](https://github.com/JuliaOpt/Ipopt.jl/issues/81).

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**Author:** ![Frank\_Kampas](https://avatars.discourse-cdn.com/v4/letter/f/a183cd/32.png) [@Frank\_Kampas](https://discourse.julialang.org/u/Frank_Kampas)\
**Post date:** [March 14, 2017, 1:54pm UTC](https://discourse.julialang.org/t/readonlymemoryerror-using-ipopt-not-fixed-in-0-51/2611/3 "2017-03-14T13:54:36Z")

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I tried the multiple step approach from xqrongm. That didn’t fix the problem

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**Author:** ![Frank\_Kampas](https://avatars.discourse-cdn.com/v4/letter/f/a183cd/32.png) [@Frank\_Kampas](https://discourse.julialang.org/u/Frank_Kampas)\
**Post date:** [March 18, 2017, 1:58pm UTC](https://discourse.julialang.org/t/readonlymemoryerror-using-ipopt-not-fixed-in-0-51/2611/4 "2017-03-18T13:58:20Z")

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The problem also exists in today’s version 0.6

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**Author:** ![miles.lubin](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/miles.lubin/32/279_2.png) [@miles.lubin](https://discourse.julialang.org/u/miles.lubin)\
**Post date:** [March 18, 2017, 3:14pm UTC](https://discourse.julialang.org/t/readonlymemoryerror-using-ipopt-not-fixed-in-0-51/2611/5 "2017-03-18T15:14:54Z")

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I cannot reproduce the issue on 64-bit 0.6.0-pre.alpha.0 with a completely clean `.julia/v0.6` directory. `Pkg.add("Ipopt")` and `Pkg.test("Ipopt")` run successfully.

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<div class="post-metadata">

**Author:** ![Frank\_Kampas](https://avatars.discourse-cdn.com/v4/letter/f/a183cd/32.png) [@Frank\_Kampas](https://discourse.julialang.org/u/Frank_Kampas)\
**Post date:** [March 18, 2017, 3:22pm UTC](https://discourse.julialang.org/t/readonlymemoryerror-using-ipopt-not-fixed-in-0-51/2611/6 "2017-03-18T15:22:32Z")

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I did the test using IJulia and didn’t change the kernel to 0.6

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**Author:** ![Frank\_Kampas](https://avatars.discourse-cdn.com/v4/letter/f/a183cd/32.png) [@Frank\_Kampas](https://discourse.julialang.org/u/Frank_Kampas)\
**Post date:** [March 24, 2017, 3:05pm UTC](https://discourse.julialang.org/t/readonlymemoryerror-using-ipopt-not-fixed-in-0-51/2611/7 "2017-03-24T15:05:35Z")

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I take it that the problem will not be fixed in 0.51

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**Author:** ![tkelman](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/tkelman/32/692_2.png) [@tkelman](https://discourse.julialang.org/u/tkelman)\
**Post date:** [March 27, 2017, 9:14pm UTC](https://discourse.julialang.org/t/readonlymemoryerror-using-ipopt-not-fixed-in-0-51/2611/8 "2017-03-27T21:14:41Z")

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It was already fixed, as far as anyone else can tell. Your WinRPM downloads are probably stale. Try running the following.

```julia
using WinRPM
pkgs = String[]
for pkg in eachline(WinRPM.installedlist)
    name = match(r"mingw64-(.*)", last(split(pkg)))
    if name !== nothing && !isempty(WinRPM.lookup(name[1]))
        push!(pkgs, name[1])
    end
end
WinRPM.install(pkgs)

```

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<div class="post-metadata">

**Author:** ![Frank\_Kampas](https://avatars.discourse-cdn.com/v4/letter/f/a183cd/32.png) [@Frank\_Kampas](https://discourse.julialang.org/u/Frank_Kampas)\
**Post date:** [March 27, 2017, 11:49pm UTC](https://discourse.julialang.org/t/readonlymemoryerror-using-ipopt-not-fixed-in-0-51/2611/9 "2017-03-27T23:49:45Z")

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Yes, that fixed the problem.