title: SymBrowser_ModifyWindowOpenWithTarget Browser Error
body: <p>We are currently using Sentry Error Tracking Software to find javascript errors. We've been receiving the following error pretty consistently:</p>
  
  <p><code>Can't find variable: SymBrowser_ModifyWindowOpenWithTarget</code></p>
  
  <p>Seems to be occurring when viewing our react webapp through a Safari browser on iOS. </p>
  
  <p>The issue is not specific to any version of iOS but seems to be mostly occurring on iOS version 11.4.1.</p>
  
  <p>I've tried to reproduce the issue myself but have had no luck, and am curious if anyone has seen this issue before.</p>