# Declaration of variable JuMP works well on ATOM but does not work on VSCODE

**URL:** https://discourse.julialang.org/t/declaration-of-variable-jump-works-well-on-atom-but-does-not-work-on-vscode/35058
**Category:** Optimization (Mathematical)
**Tags:** vscode
**Created:** [February 24, 2020, 12:07am UTC](https://discourse.julialang.org/t/declaration-of-variable-jump-works-well-on-atom-but-does-not-work-on-vscode/35058 "2020-02-24T00:07:33Z")
**Posts on this page:** 1
**Showing post:** 3

<div class="post-metadata">

### Author: ![jayce\_ram](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/jayce_ram/32/3977_2.png) [@jayce\_ram](https://discourse.julialang.org/u/jayce_ram)
#### Post date: [February 25, 2020, 5:47am UTC](https://discourse.julialang.org/t/declaration-of-variable-jump-works-well-on-atom-but-does-not-work-on-vscode/35058/3 "2020-02-25T05:47:14Z")

</div>

I got an old version of JuMP by using the command:

```julia
add JuMP@0.20.1

```

It seems to be installed successfully:

```julia
v1.3) pkg> add JuMP@0.20.1
 Resolving package versions...
 Installed Tables ────── v1.0.2
 Installed Observables ─ v0.3.0
 Installed HTTP ──────── v0.8.9
 Installed WebIO ─────── v0.8.11
 Installed JuMP ──────── v0.20.1
  Updating `~/.julia/environments/v1.3/Project.toml`
  [4076af6c] ↓ JuMP v0.21.0 ⇒ v0.20.1
  Updating `~/.julia/environments/v1.3/Manifest.toml`
  [cd3eb016] ↑ HTTP v0.8.8 ⇒ v0.8.9
  [4076af6c] ↓ JuMP v0.21.0 ⇒ v0.20.1
  [510215fc] ↑ Observables v0.2.3 ⇒ v0.3.0
  [bd369af6] ↑ Tables v1.0.1 ⇒ v1.0.2
  [0f1e0344] ↓ WebIO v0.8.13 ⇒ v0.8.11
  Building WebIO → `~/.julia/packages/WebIO/2mZPb/deps/build.log`

```

But I still got the same error.

```julia
ERROR: LoadError: MethodError: no method matching JuMP.Containers.SparseAxisArray(::Dict{Any,Any})

```

It’s necessary to do something else ?

#update  
To use an old version of a package, the steps described in the post below have worked well for me:

> [@How to pin a package to previous version on Julia 1.0?](https://discourse.julialang.org/t/how-to-pin-a-package-to-previous-version-on-julia-1-0/13661/6):
>
> The uuid refers to the package, not the version. If you want to pin a specific version, use add to obtain it, then pin to pin it. (v0.7) pkg\> add Blink [...] (v0.7) pkg\> st Status `~/.julia/environments/v0.7/Project.toml` [ad839575] Blink v0.7.0 (v0.7) pkg\> add Blink@0.6.2 Resolving package versions... Updating `~/.julia/environments/v0.7/Project.toml` [ad839575] ↓ Blink v0.7.0 ⇒ v0.6.2 Updating `~/.julia/environments/v0.7/Manifest.toml` [ad839575] ↓ Blink v0.7.0 ⇒ v0.6.2 [...]…

---

_[View the full topic](https://discourse.julialang.org/t/declaration-of-variable-jump-works-well-on-atom-but-does-not-work-on-vscode/35058)._