title: Conda install and update do not work also solving environment get errors
body: <p>I am using anaconda as below:</p>
  
  <pre><code>(base) C:\Users\xxx&gt;conda info
  
       active environment : base
      active env location : C:\Users\xxx\Documents\ANACONDA
              shell level : 1
         user config file : C:\Users\xxx\.condarc
   populated config files : C:\Users\xxx\.condarc
            conda version : 4.7.11
      conda-build version : 3.18.9
           python version : 3.6.9.final.0
         virtual packages :
         base environment : C:\Users\xxx\Documents\ANACONDA  (writable)
             channel URLs : https://repo.anaconda.com/pkgs/main/win-64
                            https://repo.anaconda.com/pkgs/main/noarch
                            https://repo.anaconda.com/pkgs/free/win-64
                            https://repo.anaconda.com/pkgs/free/noarch
                            https://repo.anaconda.com/pkgs/r/win-64
                            https://repo.anaconda.com/pkgs/r/noarch
                            https://repo.anaconda.com/pkgs/msys2/win-64
                            https://repo.anaconda.com/pkgs/msys2/noarch
            package cache : C:\Users\xxx\Documents\ANACONDA\pkgs
                            C:\Users\xxx\.conda\pkgs
                            C:\Users\xxx\AppData\Local\conda\conda\pkgs
         envs directories : C:\Users\xxx\Documents\ANACONDA\envs
                            C:\Users\xxx\.conda\envs
                            C:\Users\xxx\AppData\Local\conda\conda\envs
                 platform : win-64
               user-agent : conda/4.7.11 requests/2.22.0 CPython/3.6.9 Windows/10 Windows/10.0.16299
            administrator : False
               netrc file : None
             offline mode : False
  
  </code></pre>
  
  <p>Now I have 2 issues that stop my work.
  1) I cannot use <code>conda install</code> for any package.
  It will give me the error in <code>solving environment</code> list this:</p>
  
  <pre><code>failed with initial frozen solve. Retrying with flexible solve.
  
  </code></pre>
  
  <p>then it will fail again and give message like this:</p>
  
  <pre><code>Found conflicts! Looking for incompatible packages.
  This can take several minutes.  Press CTRL-C to abort.
  </code></pre>
  
  <p>Even after the checking for incompatible packages, it didn't give me the solution.</p>
  
  <p>2) When I want to upgrade or downgrade conda by the command:</p>
  
  <pre><code>conda update -n base conda
  </code></pre>
  
  <p>or</p>
  
  <pre><code>conda install conda = 4.6.11
  </code></pre>
  
  <p>It will give me errors again in the <code>solving environment</code>, and I think this is related to the first issue.</p>
  
  <p>Now I cannot use conda for anything, please advise and thank you!</p>