Clevershare error - no sound - fix

First, please make sure that the Mac, the Interactive Display, and the player (Youtube, VLC) are not on mute. If all are good:

In 90% of the cases forcing the app to close and reopen fixes the problem.

Right-click (click with 2 fingers, or press and hold Control while clicking) the Clevershare icon in your Dock and select Quit from the contextual menu that appears. Then, reopen the app, reconnect, and test again.

If the sound is still not going through, Quit Clevershare one more time, and open the System Preferences menu from the Apple symbol in the upper-left corner. In the window that pops up select the Security & Privacy tab. Find and click on the Microphone option on the side and remove and check back the tick next to Clevershare. You may have to unlock the menu by clicking on the lock in the lower-left corner. 

Reopen the Clevershare app and reconnect - the sound problems should be gone now.