If your session is not secure i.e. HTTP and not HTTPS, COPY AND PASTE between sessions will not function. 

You will need to use this approach

At the launch of a Cameyo session, a user will be offered the ability to ALLOW or BLOCK the clipboard.

You should always select "Allow"

If you have selected "Block"  which disables your Copy/Paste function, you will need to do the following to re-enable it:

1) In your Chrome browser, navigate to chrome://settings/content 

2) You will notice the Blocked clipboard

3) Set the Clipboard to "Allow