title: System.MissingMethodException: Method 'System.Collections.Generic.Dictionary`2.GetValueOrDefault' not found
body: <p>I'm working on <strong>Xamarin.droid</strong> application which was running fine till yesterday. But suddenly when I try to run the code I'm getting the <strong>exception on runtime</strong> once the project started to run on device </p>
  
  <blockquote>
    <p>System.MissingMethodException: Method 'System.Collections.Generic.Dictionary`2.GetValueOrDefault' not found.</p>
  </blockquote>
  
  <p>I removed all the code changes and let it be in the previous working state.<br /> Cleaned and rebuilt the project.<br /> Removed bin and obj folders.<br /> Linker property is already set to "None".<br /> Removed unnecessary packages. <br />Restarted Visual studio. Restarted the system. But still no use.<br /><br /> Using <strong><em>Visual studio enterprise 15.5.7.</em></strong></p>
  
  <p>Any help is appreciated...</p>
  
  <p><strong>Edited:</strong>
  It got resolved in my case.
  I run the app from VS, it throws the exception. Then I opened the app settings and cleared cache/data. Then opened the app. It worked as expected. Then run the app from VS. Then also it worked without throwing the exception. But don't know what exactly went wrong previously.</p>