Problems to install packages

Dear all,
When I try to install some package an error appears. For example, when I run

Pkg.add("SymEngine")

an error appears:

(@JuliaPro_v1.5.3-1) pkg> add SymEngine
ERROR: The following package names could not be resolved:
 * SymEngine (not found in project, manifest or registry)

See in the figure below:


In another day, I have installed several packages, but today no. I have already the following packages:

(@JuliaPro_v1.5.3-1) pkg> status
Status `C:\Users\Angelo\.julia\environments\JuliaPro_v1.5.3-1\Project.toml`
  [c52e3926] Atom v0.12.25 ⚲
  [5789e2e9] FileIO v1.4.5
  [2e9cd046] Gurobi v0.9.7
  [7073ff75] IJulia v1.22.0
  [c601a237] Interact v0.10.3
  [033835bb] JLD2 v0.3.2 
  [4076af6c] JuMP v0.21.5
  [e5e0dc1b] Juno v0.8.4 ⚲
  [2fda8390] LsqFit v0.12.0
  [4722fa14] PkgAuthentication v0.3.0
  [91a5bcdd] Plots v1.10.1
  [24249f21] SymPy v1.0.38
  [44d3d7a6] Weave v0.10.6
  [37e2e46d] LinearAlgebra
  [de0858da] Printf       
  [9a3f8284] Random       
  [10745b16] Statistics   

(@JuliaPro_v1.5.3-1) pkg> 

Anyone could help me please?
(I am with JuliaPro)

IIRC, JuliaPro comes with its own registry, not Julia’s General registry. So probably your error just means that SymEngine.jl is not registered with JuliaPro’s registry.

If you want to add Julia’s General registry, you should be able to run

(@JuliaPro_v1.5.3-1) pkg> registry add https://github.com/JuliaRegistries/General.git

and then adding SymEngine should work.

I’m not too familiar with JuliaPro, though, so I don’t know if using other registries will break anything.