Run the cli (command line interface) for youtube-viewer with$ youtube-viewer
Type a keyword and press enter to search for videos, and then type 1 and press enter to play the first search result. See if that gives you an error message.
Run the cli (command line interface) for youtube-viewer with$ youtube-viewer
Type a keyword and press enter to search for videos, and then type 1 and press enter to play the first search result. See if that gives you an error message.