Google has increased the security for YouTube, and some customers might experience problems sending lessons with their Google accounts.
How to fix
This procedure is simpler and allows any application to log in using your Google username and password. Follow the instructions in the link then use your Google username and password when configuring email in Swing Catalyst.
Option 2 (more secure)
Step 1: Enable two step verification
Step 2: Generate App Password
Step 3: Copy and paste the generated password into the password field. This solution is more secure as you will be generating a password specifically for sharing to YouTube within Swing Catalyst. It requires you to first enable two step authentication. Follow the instructions in the link to create a separate app password for Swing Catalyst.
It's possible to use the same app generated password for both YouTube and sharing through Gmail in Swing Catalyst.
Example email from Google
The first time you try to use Swing Catalyst with your Gmail account you may receive an email like this. The link under "If this was you" takes you to option 1 above.