title: Gunicorn 'Application Object Must Be Callable' error
body: <p>I'm trying to deploy an app written in Dash, using gunicorn and nginx. I successfully deployed this same app a few months ago, when I knew what I was doing. I wanted to make some updates and redeploy, but now the deployment wont work, even if I get rid of all my updates. When I run gunicorn, I get an error, <code>Application must be callable</code>.</p>
  
  <p>I have my project in <code>folder</code>, which contains <code>unified.py</code> file, which has my app. In <code>unified.py</code>, <code>app = dash.Dash(__name__, external_stylesheets=external_stylesheets)</code> so I'm defining my app variable as app.</p>
  
  <p>I run <code>gunicorn folder.unified:app</code> and get this error.
  However, if I run <code>from folder.unified import app</code> I get the app object and all the proper attributes, no problem. </p>
  
  <p>I have tried all sorts of variations on the gunicorn call (such as being in the project folder and saying <code>gunicorn</code>unified:app<code>, being the parent folder and using</code>gunicorn folder:app<code>,</code>gunicorn folder:unified`. I know that it can work because it was working before. But for the life of me, I cannot figure out what is going on right now.</p>
  
  <p>I expect it to run similarly to when I run the app with python using <code>python unified.py</code>.</p>
  
  <p>There was a moment where I thought I solved it because I started getting a different error (saying I couldn't get a .pkl file from another folder), but then I commented out those lines in my <code>unified.py</code> file and it went back to the same <code>Application must be callable</code> error!</p>