title: I am facing problem to install Orca in conda environment
body: <p>(D:\Anaconda3) C:\Users\Dell\Documents>conda install -c plotly plotly-orca==1.2.1 psutil requests
  Fetching package metadata ...............
  Solving package specifications: .</p>
  
  <p>Package plan for installation in environment D:\Anaconda3:</p>
  
  <p>The following NEW packages will be INSTALLED:</p>
  
  <pre><code>conda-package-handling: 1.6.1-py36h62dcd97_0
  plotly-orca:            1.2.1-1               plotly
  tqdm:                   4.46.0-py_0
  </code></pre>
  
  <p>The following packages will be UPDATED:</p>
  
  <pre><code>conda:                  4.3.27-py36hcbae3bd_0        --&gt; 4.8.3-py36_0
  conda-env:              2.6.0-h36134e3_1             --&gt; 2.6.0-1
  menuinst:               1.4.8-py36h870ab7d_0         --&gt; 1.4.16-py36he774522_0
  psutil:                 5.2.2-py36he84b5ac_0         --&gt; 5.7.0-py36he774522_0
  pycosat:                0.6.2-py36hf17546d_1         --&gt; 0.6.3-py36he774522_0
  requests:               2.18.4-py36h4371aae_1        --&gt; 2.23.0-py36_0
  vc:                     14-h2379b0c_1                --&gt; 14.1-h0510ff6_4
  vs2015_runtime:         14.0.25123-hd4c4e62_1        --&gt; 14.16.27012-hf0eaf9b_2
  </code></pre>
  
  <p>Proceed ([y]/n)? y</p>
  
  <p>ERROR conda.core.link:_execute_actions(337): An error occurred while installing package 'defaults::tqdm-4.46.0-py_0'.
  CondaError: Cannot link a source that does not exist. D:\Anaconda3\Scripts\conda.exe
  Attempting to roll back.</p>
  
  <p>CondaError: Cannot link a source that does not exist. D:\Anaconda3\Scripts\conda.exe</p>
  
  <p>(D:\Anaconda3) C:\Users\Dell\Documents></p>