That’s weird. I’m not sure why you’re getting that error. Here is the BoundsError that I’m getting:

```
BoundsError: attempt to access 2-element Vector{Float64} at index [3]
Stacktrace:
[1] setindex!(A::Vector{Float64}, x::Float64, i1::Int64)
@ Base ./array.jl:839
[2] testf!(testF::Vector{Float64}, xtest2::Vector{Float64})
@ Main ./In[150]:4
[3] (::NLSolversBase.var"#fj_finitediff!#21"{typeof(testf!), FiniteDiff.JacobianCache{Vector{Float64}, Vector{Float64}, Vector{Float64}, UnitRange{Int64}, Nothing, Val{:central}(), Float64}})(F::Vector{Float64}, J::Matrix{Float64}, x::Vector{Float64})
@ NLSolversBase ~/.julia/packages/NLSolversBase/GRQ1x/src/objective_types/oncedifferentiable.jl:138
[4] value_jacobian!!(obj::OnceDifferentiable{Vector{Float64}, Matrix{Float64}, Vector{Float64}}, F::Vector{Float64}, J::Matrix{Float64}, x::Vector{Float64})
@ NLSolversBase ~/.julia/packages/NLSolversBase/GRQ1x/src/interface.jl:124
[5] value_jacobian!!
@ ~/.julia/packages/NLSolversBase/GRQ1x/src/interface.jl:122 [inlined]
[6] trust_region_(df::OnceDifferentiable{Vector{Float64}, Matrix{Float64}, Vector{Float64}}, initial_x::Vector{Float64}, xtol::Float64, ftol::Float64, iterations::Int64, store_trace::Bool, show_trace::Bool, extended_trace::Bool, factor::Float64, autoscale::Bool, cache::NLsolve.NewtonTrustRegionCache{Vector{Float64}})
@ NLsolve ~/.julia/packages/NLsolve/gJL1I/src/solvers/trust_region.jl:119
[7] trust_region (repeats 2 times)
@ ~/.julia/packages/NLsolve/gJL1I/src/solvers/trust_region.jl:235 [inlined]
[8] nlsolve(df::OnceDifferentiable{Vector{Float64}, Matrix{Float64}, Vector{Float64}}, initial_x::Vector{Float64}; method::Symbol, xtol::Float64, ftol::Float64, iterations::Int64, store_trace::Bool, show_trace::Bool, extended_trace::Bool, linesearch::Static, linsolve::NLsolve.var"#27#29", factor::Float64, autoscale::Bool, m::Int64, beta::Int64, aa_start::Int64, droptol::Float64)
@ NLsolve ~/.julia/packages/NLsolve/gJL1I/src/nlsolve/nlsolve.jl:26
[9] nlsolve(f::Function, initial_x::Vector{Float64}; method::Symbol, autodiff::Symbol, inplace::Bool, kwargs::Base.Iterators.Pairs{Union{}, Union{}, Tuple{}, NamedTuple{(), Tuple{}}})
@ NLsolve ~/.julia/packages/NLsolve/gJL1I/src/nlsolve/nlsolve.jl:52
[10] nlsolve(f::Function, initial_x::Vector{Float64})
@ NLsolve ~/.julia/packages/NLsolve/gJL1I/src/nlsolve/nlsolve.jl:46
[11] top-level scope
@ In[151]:1
[12] eval
@ ./boot.jl:360 [inlined]
[13] include_string(mapexpr::typeof(REPL.softscope), mod::Module, code::String, filename::String)
@ Base ./loading.jl:1116
```