Issue with the gradient function

[choudharyharsh122]

I am working with Julia v1.6.7 and trying to execute this code:

W = rand(2, 5)
b = rand(2)
linear(x) = W * x .+ b
grads = gradient(() -> sum(linear(x)), Params([W, b]))

but I receive the error:

MethodError: no method matching back!(::Float64)
Closest candidates are:
back!(::Any, ::Any; once) at C:\Users\choud.julia\packages\Tracker\tdXqL\src\back.jl:74
back!(::Tracker.TrackedReal; once) at C:\Users\choud.julia\packages\Tracker\tdXqL\src\lib\real.jl:15
back!(::Tracker.TrackedArray) at C:\Users\choud.julia\packages\Tracker\tdXqL\src\lib\array.jl:68

Stacktrace:
[1] gradient_(f::var"#96#97", xs::Tracker.Params)
@ Tracker C:\Users\choud.julia\packages\Tracker\tdXqL\src\back.jl:4
[2] gradient_(f::Function, ps::Params{Zygote.Buffer{Array{Float64, N} where N, Vector{Array{Float64, N} where N}}})
@ Zygote.ZygoteTrackerExt C:\Users\choud.julia\packages\Zygote\4SSHS\ext\ZygoteTrackerExt.jl:15
[3] #gradient#689
@ C:\Users\choud.julia\packages\Tracker\tdXqL\src\back.jl:164 [inlined]
[4] gradient(f::Function, xs::Params{Zygote.Buffer{Array{Float64, N} where N, Vector{Array{Float64, N} where N}}})
@ Tracker C:\Users\choud.julia\packages\Tracker\tdXqL\src\back.jl:164
[5] top-level scope
@ In[80]:4

Does this have to do anything with the version of my Julia

[ToucheSir]

Can you please provide a full Minimal Working Example (MWE) which has all required code to run? Currently this one lacks any package imports, and I can't even tell if you're using Zygote!