# Jump code errors

**URL:** <https://discourse.julialang.org/t/jump-code-errors/34090>\
**Category:** Optimization (Mathematical)\
**Tags:** jump, optimization\
**Created:** [February 2, 2020, 6:16pm UTC](https://discourse.julialang.org/t/jump-code-errors/34090 "2020-02-02T18:16:23Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![bandaya](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/bandaya/32/12956_2.png) [@bandaya](https://discourse.julialang.org/u/bandaya)\
**Post date:** [February 2, 2020, 6:16pm UTC](https://discourse.julialang.org/t/jump-code-errors/34090/1 "2020-02-02T18:16:23Z")

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Hi, I am new to Julia and I am having problems in running simple examples of Jump.  
I have given links to two examples below:

1. [Manual · MathOptInterface](http://www.juliaopt.org/MathOptInterface.jl/release-0.5/apimanual.html#A-complete-example:-solving-a-knapsack-problem-1)
2. [https://nbviewer.jupyter.org/github/JuliaOpt/juliaopt-notebooks/blob/master/notebooks/Shuvomoy%20-%20Benders%20decomposition.ipynb](https://nbviewer.jupyter.org/github/JuliaOpt/juliaopt-notebooks/blob/master/notebooks/Shuvomoy%20-%20Benders%20decomposition.ipynb)

After a bit of googling, I found out that I have to replace “optimizer = GLPK.GLPKOptimizerMIP()” with “optimizer = GLPK.Optimizer()” in the first example. However, despite this I get the following error message: “UndefVarError: addvariables! not defined  
Stacktrace:  
[1] getproperty(::Module, ::Symbol) at .\Base.jl:13  
[2] top-level scope at In[13]:15”

Are there any examples from Jump which run with the latest version of Julia and Jump, particularly linear programming examples? I have not been able to run a single example

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<div class="post-metadata">

**Author:** ![odow](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/odow/32/28685_2.png) [@odow](https://discourse.julialang.org/u/odow)\
**Post date:** [February 2, 2020, 7:22pm UTC](https://discourse.julialang.org/t/jump-code-errors/34090/2 "2020-02-02T19:22:19Z")

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Hi there!

It seems you’ve found some old versions of the documentation.

Here’s the latest: [Quick Start Guide · JuMP](https://www.juliaopt.org/JuMP.jl/stable/quickstart/) (You can get there from the `documentation` tab at [https://jump.dev](https://jump.dev).)

If you’re interested in tutorials, you should check out: [https://github.com/JuliaOpt/JuMPTutorials.jl](https://github.com/JuliaOpt/JuMPTutorials.jl)

There are also lots of examples in the JuMP Github repository: [https://github.com/JuliaOpt/JuMP.jl/tree/release-0.20/examples](https://github.com/JuliaOpt/JuMP.jl/tree/release-0.20/examples)

Good luck!

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<div class="post-metadata">

**Author:** ![bandaya](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/bandaya/32/12956_2.png) [@bandaya](https://discourse.julialang.org/u/bandaya)\
**Post date:** [February 2, 2020, 9:23pm UTC](https://discourse.julialang.org/t/jump-code-errors/34090/3 "2020-02-02T21:23:52Z")

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Thank you for links to the updated documentation. I can now run all examples!