How to make desktop sharing in BigBlueButton?

Question

Java

I configured BBB on the server. The webinars themselves work. The file to share is downloaded, and an error occurs on startup:

com.sun.deploy.net.FailedDownloadException: Unable to load resource: file:/Users/relike/Downloads/$$jnlpUrl/lib/javacv-screenshare-0.0.1.jar
  at com.sun.deploy.net.DownloadEngine.actionDownload(Unknown Source)
  at com.sun.deploy.net.DownloadEngine.downloadResource(Unknown Source)
  at com.sun.deploy.cache.ResourceProviderImpl.getResource(Unknown Source)
  at com.sun.deploy.cache.ResourceProviderImpl.getResource(Unknown Source)
  at com.sun.javaws.LaunchDownload$DownloadTask.call(Unknown Source)
  at java.util.concurrent.FutureTask.run(FutureTask.java:266)
  at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
  at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
  at java.lang.Thread.run(Thread.java:748)

I'm running on Mac.