title: How to fix the environment with inconsistent dependencies after using conda "update" commands?
body: <p>I'm trying to update my Spyder to fix some error in my Spyder 3.2.3.</p>
  
  <p>But when I called <code>conda update spyder</code> mentioned in  (<a href="https://github.com/spyder-ide/spyder/issues/9019#event-2225858161" rel="noreferrer">https://github.com/spyder-ide/spyder/issues/9019#event-2225858161</a>), the Anaconda prompt showed as follow:</p>
  
  <p><img src="https://i.stack.imgur.com/IFWTL.png" alt="enter image description here"></p>
  
  <p>and the Spyder wasn't updated to the latest version (3.3.3).
  I guessed the reason I couldn't update Spyder is because my Conda isn't the latest version, so I ran </p>
  
  <p><code>conda update -n base -c defaults conda</code></p>
  
  <p>However after that (update conda to latest version 4.6.11) I found that all my Spyder and my Anaconda Navigator could not be opened. It seems that the commands not only update the Conda, but also update some other packages to py3.7.</p>
  
  <p>When I called <code>conda update spyder</code> again, the prompt showed as follow:</p>
  
  <pre><code>WARNING: The conda.compat module is deprecated and will be removed in a future release.
  Collecting package metadata: done
  Solving environment: |
  The environment is inconsistent, please check the package plan carefully
  The following packages are causing the inconsistency:
  
    - defaults/win-64::anaconda==5.3.1=py37_0
    - https://mirrors.ustc.edu.cn/anaconda/pkgs/free/win-64::anaconda-navigator==1.6.4=py36_0
    - defaults/win-64::astropy==3.0.4=py37hfa6e2cd_0
    - defaults/win-64::blaze==0.11.3=py37_0
    - defaults/win-64::bottleneck==1.2.1=py37h452e1ab_1
    - defaults/win-64::dask==0.19.1=py37_0
    - defaults/win-64::datashape==0.5.4=py37_1
    - defaults/win-64::h5py==2.8.0=py37h3bdd7fb_2
    - defaults/win-64::imageio==2.4.1=py37_0
    - defaults/win-64::matplotlib==2.2.3=py37hd159220_0
    - defaults/win-64::mkl-service==1.1.2=py37hb217b18_5
    - defaults/win-64::mkl_fft==1.0.4=py37h1e22a9b_1
    - defaults/win-64::mkl_random==1.0.1=py37h77b88f5_1
    - defaults/win-64::numba==0.39.0=py37h830ac7b_0
    - defaults/win-64::numexpr==2.6.8=py37h9ef55f4_0
    - defaults/win-64::numpy-base==1.15.1=py37h8128ebf_0
    - defaults/win-64::odo==0.5.1=py37_0
    - defaults/win-64::pandas==0.23.4=py37h830ac7b_0
    - defaults/win-64::patsy==0.5.0=py37_0
    - defaults/win-64::pytables==3.4.4=py37he6f6034_0
    - defaults/win-64::pytest-arraydiff==0.2=py37h39e3cac_0
    - defaults/win-64::pytest-astropy==0.4.0=py37_0
    - defaults/win-64::pytest-doctestplus==0.1.3=py37_0
    - defaults/win-64::pywavelets==1.0.0=py37h452e1ab_0
    - defaults/win-64::scikit-image==0.14.0=py37h6538335_1
    - defaults/win-64::scikit-learn==0.19.2=py37heebcf9a_0
    - defaults/win-64::scipy==1.1.0=py37h4f6bf74_1
    - defaults/win-64::seaborn==0.9.0=py37_0
    - defaults/win-64::statsmodels==0.9.0=py37h452e1ab_0
  done
  # All requested packages already installed.
  </code></pre>
  
  <p>I guess maybe the python version conflict (my python version is 3.6.2) causes the exception of the Spyder and Navigator. So I try to restore these packages to py3.6 version by called <code>conda install python = 3.6</code>, but it doesn't works.</p>
  
  <p>This is the result of <code>conda list -version</code>(the last 2 rev)</p>
  
  <pre><code>2019-04-09 22:59:08  (rev 3)
        certifi  {2016.2.28 (https://mirrors.ustc.edu.cn/anaconda/pkgs/free) -&gt; 2019.3.9}
        conda  {4.5.13 -&gt; 4.6.11}
        cryptography  {1.8.1 (https://mirrors.ustc.edu.cn/anaconda/pkgs/free) -&gt; 2.6.1}
        curl  {7.52.1 (https://mirrors.ustc.edu.cn/anaconda/pkgs/free) -&gt; 7.64.0}
        libcurl  {7.61.0 -&gt; 7.64.0}
        libpng  {1.6.34 -&gt; 1.6.36}
        libprotobuf  {3.2.0 (https://mirrors.ustc.edu.cn/anaconda/pkgs/free) -&gt; 3.6.1}
        libssh2  {1.8.0 (https://mirrors.ustc.edu.cn/anaconda/pkgs/free) -&gt; 1.8.0}
        menuinst  {1.4.7 (https://mirrors.ustc.edu.cn/anaconda/pkgs/free) -&gt; 1.4.16}
        openssl  {1.0.2l (https://mirrors.ustc.edu.cn/anaconda/pkgs/free) -&gt; 1.1.1b}
        protobuf  {3.2.0 (https://mirrors.ustc.edu.cn/anaconda/pkgs/free) -&gt; 3.6.1}
        pycurl  {7.43.0 (https://mirrors.ustc.edu.cn/anaconda/pkgs/free) -&gt; 7.43.0.2}
        pyqt  {5.6.0 (https://mirrors.ustc.edu.cn/anaconda/pkgs/free) -&gt; 5.9.2}
        python  {3.6.2 (https://mirrors.ustc.edu.cn/anaconda/pkgs/free) -&gt; 3.6.8}
        qt  {5.6.2 -&gt; 5.9.7}
        requests  {2.14.2 (https://mirrors.ustc.edu.cn/anaconda/pkgs/free) -&gt; 2.21.0}
        sip  {4.18 (https://mirrors.ustc.edu.cn/anaconda/pkgs/free) -&gt; 4.19.8}
        sqlite  {3.24.0 -&gt; 3.27.2}
        vc  {14 (https://mirrors.ustc.edu.cn/anaconda/pkgs/free) -&gt; 14.1}
       +krb5-1.16.1
  
   2019-04-09 23:02:48  (rev 4)
        cryptography  {2.6.1 -&gt; 1.8.1 (https://mirrors.ustc.edu.cn/anaconda/pkgs/free)}
        curl  {7.64.0 -&gt; 7.52.1 (https://mirrors.ustc.edu.cn/anaconda/pkgs/free)}
        krb5  {1.16.1 -&gt; 1.13.2 (https://mirrors.ustc.edu.cn/anaconda/pkgs/free)}
        libcurl  {7.64.0 -&gt; 7.61.1}
        libpng  {1.6.36 -&gt; 1.6.34}
        libprotobuf  {3.6.1 -&gt; 3.2.0 (https://mirrors.ustc.edu.cn/anaconda/pkgs/free)}
        libssh2  {1.8.0 -&gt; 1.8.0 (https://mirrors.ustc.edu.cn/anaconda/pkgs/free)}
        menuinst  {1.4.16 -&gt; 1.4.14}
        openssl  {1.1.1b -&gt; 1.0.2l (https://mirrors.ustc.edu.cn/anaconda/pkgs/free)}
        protobuf  {3.6.1 -&gt; 3.2.0 (https://mirrors.ustc.edu.cn/anaconda/pkgs/free)}
        pycurl  {7.43.0.2 -&gt; 7.43.0 (https://mirrors.ustc.edu.cn/anaconda/pkgs/free)}
        pyqt  {5.9.2 -&gt; 5.6.0 (https://mirrors.ustc.edu.cn/anaconda/pkgs/free)}
        python  {3.6.8 -&gt; 3.6.2 (https://mirrors.ustc.edu.cn/anaconda/pkgs/free)}
        qt  {5.9.7 -&gt; 5.6.2}
        sqlite  {3.27.2 -&gt; 3.25.2}
        vc  {14.1 -&gt; 14 (https://mirrors.ustc.edu.cn/anaconda/pkgs/free)}
  </code></pre>
  
  <p>This is the result of <code>conda info</code></p>
  
  <pre><code>     active environment : base
      active env location : C:\Users\lenovo\Anaconda3
              shell level : 1
         user config file : C:\Users\lenovo\.condarc
   populated config files : C:\Users\lenovo\.condarc
            conda version : 4.6.11
      conda-build version : 3.0.19
           python version : 3.6.2.final.0
         base environment : C:\Users\lenovo\Anaconda3  (writable)
             channel URLs : https://mirrors.ustc.edu.cn/anaconda/pkgs/free/win-64
                            https://mirrors.ustc.edu.cn/anaconda/pkgs/free/noarch
                            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\lenovo\Anaconda3\pkgs
                            C:\Users\lenovo\.conda\pkgs
                            C:\Users\lenovo\AppData\Local\conda\conda\pkgs
         envs directories : C:\Users\lenovo\Anaconda3\envs
                            C:\Users\lenovo\.conda\envs
                            C:\Users\lenovo\AppData\Local\conda\conda\envs
                 platform : win-64
               user-agent : conda/4.6.11 requests/2.21.0 CPython/3.6.2 Windows/10 Windows/10.0.17134
            administrator : False
               netrc file : None
             offline mode : False
  </code></pre>
  
  <p>What is the best way to fix the issue?</p>
  
  <p>How can I get my Spyder to work again?</p>