# Cannot assign a value to variable workspace

**URL:** <https://discourse.julialang.org/t/cannot-assign-a-value-to-variable-workspace/56613>\
**Category:** Optimization (Mathematical)\
**Tags:** question\
**Created:** [March 6, 2021, 12:31pm UTC](https://discourse.julialang.org/t/cannot-assign-a-value-to-variable-workspace/56613 "2021-03-06T12:31:01Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![priod](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/priod/32/53099_2.png) [@priod](https://discourse.julialang.org/u/priod)\
**Post date:** [March 6, 2021, 12:31pm UTC](https://discourse.julialang.org/t/cannot-assign-a-value-to-variable-workspace/56613/1 "2021-03-06T12:31:01Z")

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I am using Ipopt optimizer in a problem, I have created a variable name inside the model in an array form, for instance, (k,p[1:2]), after running the specific cell, it is giving me the error, that _cannot assign a value to variable workspace142.p from module workspace159_,

Could anybody suggest to me, how to get rid of this problem? Thanking you in advance!

 ![11](https://global.discourse-cdn.com/julialang/original/3X/6/b/6b2258c22dfd24d942c4bfd972536e835d1c15f2.png)

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**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:** [March 6, 2021, 6:30pm UTC](https://discourse.julialang.org/t/cannot-assign-a-value-to-variable-workspace/56613/2 "2021-03-06T18:30:49Z")

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JuMP doesn’t work in pluto because pluto doesn’t understand macros or mutation of structs.

Edit: here are the relevant issues: [https://github.com/fonsp/Pluto.jl/issues/196](https://github.com/fonsp/Pluto.jl/issues/196), [https://github.com/fonsp/Pluto.jl/issues/564](https://github.com/fonsp/Pluto.jl/issues/564)