Update Conda vs update Julia 1.5.2

After successfully performing the Coda update:

using Conda
[ Info: Precompiling Conda [8f4d0f93-b110-5947-807f-2305c1781a2d]

julia> Conda.ROOTENV
"C:\\Users\\user\\.julia\\conda\\3"

julia> Conda.update()
[ Info: Running `conda update -y --all conda` in root environment
Collecting package metadata (current_repodata.json): done
Solving environment: done

## Package Plan ##

  environment location: C:\Users\user\.julia\conda\3

  added / updated specs:
    - conda


The following packages will be downloaded:

    package                    |            build
    ---------------------------|-----------------
    async_generator-1.10       |             py_0          24 KB
    attrs-20.2.0               |             py_0          42 KB
                              ***
zipp-3.3.1                 |             py_0          12 KB
    ------------------------------------------------------------
                                           Total:        56.0 MB

The following NEW packages will be INSTALLED:

  async_generator    pkgs/main/noarch::async_generator-1.10-py_0
  jupyterlab_pygmen~ pkgs/main/noarch::jupyterlab_pygments-0.1.2-py_0
  nbclient           pkgs/main/noarch::nbclient-0.5.1-py_0
  nest-asyncio       pkgs/main/noarch::nest-asyncio-1.4.1-py_0

The following packages will be UPDATED:

  attrs                                         20.1.0-py_0 --> 20.2.0-py_0
  ***
Preparing transaction: done
Verifying transaction: done
Executing transaction: / DEBUG menuinst_win32:__init__(198): Menu: name: 'Anaconda${PY_VER} ${PLATFORM}', prefix: 'C:\Users\user\.julia\conda\3', env_name: 'None', mode: 'user', used_mode: 'user'
DEBUG menuinst_win32:create(323): Shortcut cmd is C:\Users\user\.julia\conda\3\python.exe, args are ['C:\\Users\\user\\.julia\\conda\\3\\cwp.py', 'C:\\Users\\user\\.julia\\conda\\3', 'C:\\Users\\user\\.julia\\conda\\3\\python.exe', 'C:\\Users\\user\\.julia\\conda\\3\\Scripts\\jupyter-notebook-script.py', '"%USERPROFILE%/"']
\ DEBUG menuinst_win32:__init__(198): Menu: name: 'Anaconda${PY_VER} ${PLATFORM}', prefix: 'C:\Users\user\.julia\conda\3', env_name: 'None', mode: 'user', used_mode: 'user'
DEBUG menuinst_win32:create(323): Shortcut cmd is C:\Users\user\.julia\conda\3\python.exe, args are ['C:\\Users\\user\\.julia\\conda\\3\\cwp.py', 'C:\\Users\\user\\.julia\\conda\\3', 'C:\\Users\\user\\.julia\\conda\\3\\python.exe', 'C:\\Users\\user\\.julia\\conda\\3\\Scripts\\jupyter-notebook-script.py', '"%USERPROFILE%/"']
/ DEBUG menuinst_win32:__init__(198): Menu: name: 'Anaconda${PY_VER} ${PLATFORM}', prefix: 'C:\Users\user\.julia\conda\3', env_name: 'None', mode: 'user', used_mode: 'user'
DEBUG menuinst_win32:create(323): Shortcut cmd is C:\Users\user\.julia\conda\3\python.exe, args are ['C:\\Users\\user\\.julia\\conda\\3\\cwp.py', 'C:\\Users\\user\\.julia\\conda\\3', 'C:\\Users\\user\\.julia\\conda\\3\\python.exe', 'C:\\Users\\user\\.julia\\conda\\3\\Scripts\\jupyter-notebook-script.py', '"%USERPROFILE%/"']
done

I receive the following alert when I want to update Julia

               _
   _       _ _(_)_     |  Documentation: https://docs.julialang.org
  (_)     | (_) (_)    |
   _ _   _| |_  __ _   |  Type "?" for help, "]?" for Pkg help.
  | | | | | | |/ _` |  |
  | | |_| | | | (_| |  |  Version 1.5.2 (2020-09-23)
 _/ |\__'_|_|_|\__'_|  |  Official https://julialang.org/ release
|__/                   |

(@v1.5) pkg> up
 Installing known registries into `C:\Users\user\.julia`
ERROR: SystemError: opening file "C:\\Users\\user\\.julia\\registries\\General\\Registry.toml": No such file or directory
Stacktrace:
 [1] systemerror(::String, ::Int32; extrainfo::Nothing) at .\error.jl:168
 [2] #systemerror#48 at .\error.jl:167 [inlined]
 [3] systemerror at .\error.jl:167 [inlined]
 [4] open(::String; lock::Bool, read::Nothing, write::Nothing, create::Nothing, truncate::Nothing, append::Nothing) at .\iostream.jl:284
 [5] open at .\iostream.jl:273 [inlined]
 [6] open(::Base.var"#294#295"{Tuple{}}, ::String; kwargs::Base.Iterators.Pairs{Union{},Union{},Tuple{},NamedTuple{(),Tuple{}}}) at .\io.jl:323
 [7] open at .\io.jl:323 [inlined]
 [8] read at .\io.jl:408 [inlined]
 [9] parsefile at D:\buildbot\worker\package_win64\build\usr\share\julia\stdlib\v1.5\Pkg\ext\TOML\src\TOML.jl:50 [inlined]
 [10] read_registry(::String; cache::Bool) at D:\buildbot\worker\package_win64\build\usr\share\julia\stdlib\v1.5\Pkg\src\Types.jl:1044
 [11] read_registry at D:\buildbot\worker\package_win64\build\usr\share\julia\stdlib\v1.5\Pkg\src\Types.jl:1039 [inlined]
 [12] (::Pkg.Types.var"#94#97"{Pkg.Types.Context,String,Pkg.Types.RegistrySpec})(::String) at D:\buildbot\worker\package_win64\build\usr\share\julia\stdlib\v1.5\Pkg\src\Types.jl:1016
 [13] mktempdir(::Pkg.Types.var"#94#97"{Pkg.Types.Context,String,Pkg.Types.RegistrySpec}, ::String; prefix::String) at .\file.jl:682
 [14] mktempdir at .\file.jl:680 [inlined] (repeats 2 times)
 [15] clone_or_cp_registries(::Pkg.Types.Context, ::Array{Pkg.Types.RegistrySpec,1}, ::String) at D:\buildbot\worker\package_win64\build\usr\share\julia\stdlib\v1.5\Pkg\src\Types.jl:980
 [16] clone_or_cp_registries at D:\buildbot\worker\package_win64\build\usr\share\julia\stdlib\v1.5\Pkg\src\Types.jl:973 [inlined]
 [17] clone_default_registries(::Pkg.Types.Context; only_if_empty::Bool) at D:\buildbot\worker\package_win64\build\usr\share\julia\stdlib\v1.5\Pkg\src\Types.jl:874
 [18] clone_default_registries at D:\buildbot\worker\package_win64\build\usr\share\julia\stdlib\v1.5\Pkg\src\Types.jl:862 [inlined]
 [19] up(::Pkg.Types.Context, ::Array{Pkg.Types.PackageSpec,1}; level::Pkg.Types.UpgradeLevel, mode::Pkg.Types.PackageMode, update_registry::Bool, kwargs::Base.Iterators.Pairs{Union{},Union{},Tuple{},NamedTuple{(),Tuple{}}}) at D:\buildbot\worker\package_win64\build\usr\share\julia\stdlib\v1.5\Pkg\src\API.jl:226
 [20] up at D:\buildbot\worker\package_win64\build\usr\share\julia\stdlib\v1.5\Pkg\src\API.jl:221 [inlined]
 [21] #up#37 at D:\buildbot\worker\package_win64\build\usr\share\julia\stdlib\v1.5\Pkg\src\API.jl:67 [inlined]
 [22] up(::Array{Pkg.Types.PackageSpec,1}) at D:\buildbot\worker\package_win64\build\usr\share\julia\stdlib\v1.5\Pkg\src\API.jl:67
 [23] do_cmd!(::Pkg.REPLMode.Command, ::REPL.LineEditREPL) at D:\buildbot\worker\package_win64\build\usr\share\julia\stdlib\v1.5\Pkg\src\REPLMode\REPLMode.jl:404
 [24] do_cmd(::REPL.LineEditREPL, ::String; do_rethrow::Bool) at D:\buildbot\worker\package_win64\build\usr\share\julia\stdlib\v1.5\Pkg\src\REPLMode\REPLMode.jl:382
 [25] do_cmd at D:\buildbot\worker\package_win64\build\usr\share\julia\stdlib\v1.5\Pkg\src\REPLMode\REPLMode.jl:377 [inlined]
 [26] (::Pkg.REPLMode.var"#24#27"{REPL.LineEditREPL,REPL.LineEdit.Prompt})(::REPL.LineEdit.MIState, ::Base.GenericIOBuffer{Array{UInt8,1}}, ::Bool) at D:\buildbot\worker\package_win64\build\usr\share\julia\stdlib\v1.5\Pkg\src\REPLMode\REPLMode.jl:546
 [27] #invokelatest#1 at .\essentials.jl:710 [inlined]
 [28] invokelatest at .\essentials.jl:709 [inlined]
 [29] run_interface(::REPL.Terminals.TextTerminal, ::REPL.LineEdit.ModalInterface, ::REPL.LineEdit.MIState) at D:\buildbot\worker\package_win64\build\usr\share\julia\stdlib\v1.5\REPL\src\LineEdit.jl:2355
 [30] run_frontend(::REPL.LineEditREPL, ::REPL.REPLBackendRef) at D:\buildbot\worker\package_win64\build\usr\share\julia\stdlib\v1.5\REPL\src\REPL.jl:1144
 [31] (::REPL.var"#38#42"{REPL.LineEditREPL,REPL.REPLBackendRef})() at .\task.jl:356

The registry is corrupt for some reason. Try registry rm General and then up and it should reinstall.

1.Removed the registries folder.
2 Pkg> up.
Problem solved!!