Only the main calendar from my Google Account syncs to the Calendar app
Solution 1:
Someone posted a working solution on Microsoft Answers:
- Download User Agent Switcher from the Chrome Webstore
- Select an iOS device
- Go to http://m.google.com/sync
- Deactivate Javascript in Settings (
Show advanced settings,Content settings) - Click your Windows Mail device
- In the URL change
supportMultipleCalendars=falsetosupportMultipleCalendars=true - Save
- Readd your Google Account to your Windows Calendar app. It now works.