Sometimes Google will update their systems and it "breaks" the connection to your calendar.
To reconnect your calendar in The Follow Up Ninja:
Log In to your Follow Up Ninja account
Scroll the left menu to "Settings"
Click "Settings"
Click "Integrations"
Under "Google Account" click the green letters that say "connected"
**It may show "connected" under your calendar, but still click this button.
This will disconnect your calendar.
Click "Connect" to reconnect the Google Calendar