Jigsaw's Chrome Extension for Desktop Sharing is no longer required to screen share. You can remove that from your extensions. The extension is now optional.
How to Install the Jigsaw Extension (Optional)
If you ever find a situation when Screen Sharing is not working for you, and all you need to do is share your screen (i.e. no need to use Remote Access, Copy & Paste to the Whiteboard, or Insert Screenshot from Pane 2 to the Whiteboard), then you can install the Extension for Screen Sharing purposes.
1. Click the Chrome menu in the upper right corner of the browser.
2. Select More Tools.
3. Click Extensions.
4. Click the Extension menu in the upper left corner.
5. Click Open Chrome Web Store at bottom of panel.
6. In the search box, type Jigsaw Desktop Sharing.
7. Click Add to Chrome when the app appears.
8. Choose Add Extension
9. Once added, you will receive a confirmation.