Hi GLC,
Two thoughts...
1. Do you have Java installed?
If not, then install Java at
Ignore the warning that Java won't run inside your browser. BigBlueButton uses Java Network Launch Protocol file (screenshare.jnlp) to launch Java outside the browser.
2. If yes to (1), then take a look at the screenshare.jnlp icon -- is it a Java icon?
If not, you need to set the file association (right-click on the icon and choose properties).
Then check the text for "Opens with:"
The “Opens with:” shoud say Java(™) Web Start Launcher. If not, click the Change button. This will show a dialog asking how to open .jnlp files.
Click More apps. Scroll down until you see “Look for another app on this PC”.
Click “Look for another app on this PC”. Navigate to c:\Program Files\Java\jre1.8.0_151\bin (or later version).
Choose javaws and click Open.
If you look at the icon for the file screenshare.jnlp file should now show the Java icon.
Try the above and let us know if that gets you going with desktop sharing.
Regards,.. Fred