# Type problem running old julia codes

**URL:** <https://discourse.julialang.org/t/type-problem-running-old-julia-codes/123993>\
**Category:** General Usage\
**Tags:** question\
**Created:** [December 19, 2024, 1:30pm UTC](https://discourse.julialang.org/t/type-problem-running-old-julia-codes/123993 "2024-12-19T13:30:36Z")\
**Posts on this page:** 3\
**Page:** 2

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**Author:** ![ufechner7](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/ufechner7/32/51363_2.png) [@ufechner7](https://discourse.julialang.org/u/ufechner7)\
**Post date:** [December 23, 2024, 2:37am UTC](https://discourse.julialang.org/t/type-problem-running-old-julia-codes/123993/21 "2024-12-23T02:37:00Z")

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> [@jiang\_ming\_zhang](#):
>
> `Error: '1.10' is not an installed Julia version, run `juliaup add 1.10` first.`

Reading the error message helps!

What happens if you run

```julia
juliaup add 1.10
juliaup default 1.10

```

?

---

<div class="post-metadata">

**Author:** ![jiang\_ming\_zhang](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/jiang_ming_zhang/32/204063_2.png) [@jiang\_ming\_zhang](https://discourse.julialang.org/u/jiang_ming_zhang)\
**Post date:** [December 23, 2024, 2:43am UTC](https://discourse.julialang.org/t/type-problem-running-old-julia-codes/123993/22 "2024-12-23T02:43:42Z")

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It works. But it is strange. I did not delete the 1.10 julia. I just added 0.7 julia.

There should be no need of re-installing.

```julia
C:\Users\jmzhang>juliaup add 1.10
Installing Julia 1.10.7+0.x64.w64.mingw32

C:\Users\jmzhang>juliaup default 1.10
Configured the default Julia version to be '1.10'.

C:\Users\jmzhang>julia
               _
   _ _ _(_)_ | Documentation: https://docs.julialang.org
  (_) | (_) (_) |
   _ _ _| |_ __ _ | Type "?" for help, "]?" for Pkg help.
  | | | | | | |/ _` | |
  | | |_| | | | (_| | | Version 1.10.7 (2024-11-26)
 _/ |\ __'_|_|_|\__'_| | Official https://julialang.org/ release
|__/ |

```

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<div class="post-metadata">

**Author:** ![Zentrik](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/zentrik/32/35409_2.png) [@Zentrik](https://discourse.julialang.org/u/Zentrik)\
**Post date:** [December 23, 2024, 9:26am UTC](https://discourse.julialang.org/t/type-problem-running-old-julia-codes/123993/23 "2024-12-23T09:26:43Z")

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I’m guessing your previous Julia installation didn’t use `juliaup`. Installing `juliaup` makes running `julia` only show versions installed using juliaup which is why you had to install 1.10.

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