# Error: MethodError: no method matching validate

**URL:** <https://discourse.julialang.org/t/error-methoderror-no-method-matching-validate/123354>\
**Category:** New to Julia\
**Tags:** question, package, catalyst\
**Created:** [December 2, 2024, 11:37am UTC](https://discourse.julialang.org/t/error-methoderror-no-method-matching-validate/123354 "2024-12-02T11:37:33Z")\
**Posts on this page:** 10\
**Page:** 1

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**Author:** ![Jax\_Xu](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/jax_xu/32/213903_2.png) [@Jax\_Xu](https://discourse.julialang.org/u/Jax_Xu)\
**Post date:** [December 2, 2024, 11:37am UTC](https://discourse.julialang.org/t/error-methoderror-no-method-matching-validate/123354/1 "2024-12-02T11:37:33Z")

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Hi! I’m new to Julia and Catalyst.jl. I am trying to follow the tutorial of _Introduction_ to learn how to use catalyst. I install packages, including

> Blockquote  
> Status `C:\Users\23954749\.julia\environments\v1.10\Project.toml`  
> ⌃ [479239e8] Catalyst v12.1.1  
> ⌃ [0c46a032] DifferentialEquations v6.20.0  
> [f80590ac] JuliaFEM v0.5.1  
> ⌅ [98e50ef6] JuliaFormatter v0.15.11  
> ⌅ [961ee093] ModelingToolkit v6.4.9  
> [2774e3e8] NLsolve v4.5.1  
> ⌅ [1dea7af3] OrdinaryDiffEq v5.71.2  
> [91a5bcdd] Plots v1.40.9  
> ⌅ [47a9eef4] SparseDiffTools v1.21.0  
> [24249f21] SymPy v2.2.1  
> Info Packages marked with ⌃ and ⌅ have new versions available. Those with ⌃ may be upgradable, but those with ⌅ are restricted by compatibility constraints from upgrading. To see why use `status --outdated`

I directly copied the codes in tutorial of constructing the reaction network, as shown below,

> Blockquote  
> using Catalyst  
> using OrdinaryDiffEq  
> using Plots  
> rn = @reaction\_network begin  
> b, 0 → X  
> d, X → 0  
> end

Julia returned errors that I can’t solve, which I hope to get helped so I can keep going on.

> Blockquote  
> ERROR: MethodError: no method matching validate(::ReactionSystem{Nothing, Catalyst.NetworkProperties{Int64, Term{Real, Base.ImmutableDict{DataType, Any}}}})

Closest candidates are:  
validate(::Equation; info)  
@ ModelingToolkit C:\Users\23954749.julia\packages\ModelingToolkit\0dKHa\src\systems\validation.jl:185  
validate(::Equation, ::Union{Num, SymbolicUtils.Symbolic, Unitful.Quantity}; info)  
@ ModelingToolkit C:\Users\23954749.julia\packages\ModelingToolkit\0dKHa\src\systems\validation.jl:186  
validate(::Equation, ::Vector; info)  
@ ModelingToolkit C:\Users\23954749.julia\packages\ModelingToolkit\0dKHa\src\systems\validation.jl:187  
…

Stacktrace:  
[1] ReactionSystem(eqs::Vector{…}, iv::Sym{…}, states::Vector{…}, ps::Vector{…}, var\_to\_name::Dict{…}, observed::Vector{…}, name::Symbol, systems::Vector{…}, defaults::Dict{…}, connection\_type::Nothing, csys::Nothing, nps::Catalyst.NetworkProperties{…}, cls::Bool; checks::Bool)  
@ Catalyst C:\Users\23954749.julia\packages\Catalyst\JocXA\src\reactionsystem.jl:460  
[2] ReactionSystem(eqs::Vector{…}, iv::Sym{…}, states::Vector{…}, ps::Vector{…}; observed::Vector{…}, systems::Vector{…}, name::Symbol, default\_u0::Dict{…}, default\_p::Dict{…}, defaults::Dict{…}, connection\_type::Nothing, checks::Bool, constraints::Nothing, networkproperties::Nothing, combinatoric\_ratelaws::Bool, balanced\_bc\_check::Bool)  
@ Catalyst C:\Users\23954749.julia\packages\Catalyst\JocXA\src\reactionsystem.jl:547  
[3] make\_ReactionSystem\_internal(rxs::Vector{…}, iv::Num, no\_sps::Nothing, ps\_in::Vector{…}; kwargs::@Kwargs{…})  
@ Catalyst C:\Users\23954749.julia\packages\Catalyst\JocXA\src\reactionsystem.jl:597  
[4] top-level scope  
@ C:\Users\23954749.julia\packages\Catalyst\JocXA\src\reaction\_network.jl:282

Thank you!

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<div class="post-metadata">

**Author:** ![Jax\_Xu](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/jax_xu/32/213903_2.png) [@Jax\_Xu](https://discourse.julialang.org/u/Jax_Xu)\
**Post date:** [December 2, 2024, 11:48am UTC](https://discourse.julialang.org/t/error-methoderror-no-method-matching-validate/123354/3 "2024-12-02T11:48:10Z")

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I have been reading the other similar questions in Julia Forum. Their ‘error: no method matching’ is often relevant to the specific function or expression in their codes. That came to my blindside: I didn’t call ‘validate’ function, which I assume should be embedded in the package or somewhere that the experienced developers did. I don’t know if this could be a stupid question, but I would really appreciate it if somebody could help me out. Thanks!

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**Author:** ![nilshg](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/nilshg/32/2283_2.png) [@nilshg](https://discourse.julialang.org/u/nilshg)\
**Post date:** [December 2, 2024, 11:58am UTC](https://discourse.julialang.org/t/error-methoderror-no-method-matching-validate/123354/4 "2024-12-02T11:58:24Z")

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You are on Catalyst v12 which is at this point two and a half years old, while the current release is 14.4.1.

Make sure you either read the documentation for v12, or update to v14 if you’re reading the latest docs.

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**Author:** ![Jax\_Xu](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/jax_xu/32/213903_2.png) [@Jax\_Xu](https://discourse.julialang.org/u/Jax_Xu)\
**Post date:** [December 2, 2024, 12:07pm UTC](https://discourse.julialang.org/t/error-methoderror-no-method-matching-validate/123354/5 "2024-12-02T12:07:19Z")

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Yes! I noticed and I tried both documentations of catalyst v12 and v14. They returned the same error. I’m using VS Code for Julia. I don’t know if that could be the problem, such as missing packages to support catalyst.jl.

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<div class="post-metadata">

**Author:** ![nilshg](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/nilshg/32/2283_2.png) [@nilshg](https://discourse.julialang.org/u/nilshg)\
**Post date:** [December 2, 2024, 1:35pm UTC](https://discourse.julialang.org/t/error-methoderror-no-method-matching-validate/123354/6 "2024-12-02T13:35:55Z")

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I’m not sure where in the docs you get your example from, but in any event here’s what I get on Julia 1.11.1:

```julia
(jl_hXzRfb) pkg> st
Status `(...)\Temp\jl_hXzRfb\Project.toml`
  [479239e8] Catalyst v14.4.1
  [1dea7af3] OrdinaryDiffEq v6.90.1

julia> using Catalyst, OrdinaryDiffEq

julia> rn = @reaction_network begin
       b, 0 --> X
       d, X --> 0
       end
Model ##ReactionSystem#250:
Unknowns (1): see unknowns(##ReactionSystem#250)
  X(t)
Parameters (2): see parameters(##ReactionSystem#250)
  b
  d

```

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<div class="post-metadata">

**Author:** ![Jax\_Xu](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/jax_xu/32/213903_2.png) [@Jax\_Xu](https://discourse.julialang.org/u/Jax_Xu)\
**Post date:** [December 2, 2024, 4:06pm UTC](https://discourse.julialang.org/t/error-methoderror-no-method-matching-validate/123354/7 "2024-12-02T16:06:32Z")

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Problem solved~! After reading your comment, I am pretty sure something should go wrong with my Julia. So I uninstalled Julia and deleted all folders, and I re-installed Julia and catalyst. Everything worked out! I guess this problem could be the conflict of my tons of packages.  
Such a long day! feels like an ambitious man stumbled down in his first step out because he is too equipped. 😂

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<div class="post-metadata">

**Author:** ![nilshg](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/nilshg/32/2283_2.png) [@nilshg](https://discourse.julialang.org/u/nilshg)\
**Post date:** [December 2, 2024, 4:07pm UTC](https://discourse.julialang.org/t/error-methoderror-no-method-matching-validate/123354/8 "2024-12-02T16:07:55Z")

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> [@Jax\_Xu](#):
>
> I guess this problem could be the conflict of my tons of packages.

This is very likely, make sure to do your work in minimal project specific environments containing only the packages you really need for the task at hand:

> **[4. Working with Environment · Pkg.jl](https://pkgdocs.julialang.org/v1/environments/)**
>
> Documentation for Pkg.jl.

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<div class="post-metadata">

**Author:** ![Jax\_Xu](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/jax_xu/32/213903_2.png) [@Jax\_Xu](https://discourse.julialang.org/u/Jax_Xu)\
**Post date:** [December 2, 2024, 4:08pm UTC](https://discourse.julialang.org/t/error-methoderror-no-method-matching-validate/123354/9 "2024-12-02T16:08:08Z")

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I will delete this question in 3 days. Thank you for the community! If any newbies met similar problems like I did. Just re-install Julia and Catalyst~ 😇

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<div class="post-metadata">

**Author:** ![nilshg](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/nilshg/32/2283_2.png) [@nilshg](https://discourse.julialang.org/u/nilshg)\
**Post date:** [December 2, 2024, 4:10pm UTC](https://discourse.julialang.org/t/error-methoderror-no-method-matching-validate/123354/10 "2024-12-02T16:10:39Z")

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No need to delete - you never know who might stumble upon this and find it helpful in future.

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<div class="post-metadata">

**Author:** ![Jax\_Xu](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/jax_xu/32/213903_2.png) [@Jax\_Xu](https://discourse.julialang.org/u/Jax_Xu)\
**Post date:** [December 2, 2024, 4:14pm UTC](https://discourse.julialang.org/t/error-methoderror-no-method-matching-validate/123354/11 "2024-12-02T16:14:02Z")

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You are right! I hope my experience could help the other new users of Julia! Thank you Nilshg! 🥰