Is the error message "Cannot Create Account: An identical Subscribed Calendar account already exists" displaying when you click the + Add schedule to iOS Calendar button on your team schedule page?
Double check to see if you are already subscribed to the calendar on another device (Mac, iPad, iPhone, iCloud). A common issue with this error is that users have already subscribed on another device that their device can see exists, but the subscription is not carried through to that device's calendar. Check to see if the calendar is attempting to push over iCloud somewhere as this is not supported anymore. If you are able to locate it, please try removing the subscription from the original device using the instructions here: Unsubscribing from a Team Schedule
Here are some tips for checking the settings of your devices to locate the subscription:
Check settings on your iPhone and/or iPad
- Go to the Settings app
- Go to Mail, Contacts, Calendars
- Go to Subscribed Calendars
- Is iCloud>Calendars turned on?
Check the iOS calendar app on your iPhone and/or iPad
- Go to iOS calendar app
- Click on Calendars (listed at the bottom of the page)
- Is the team name listed here?
- Is there a checkmark next to the team name?
- Is the calendar listed under iCloud?
Check iCal on your Mac
- Open up iCal
- Click on the Calendar button (top left-hand side of the calendar) to show all your calendars
- Is the calendar listed under iCloud or Other?
- Click "Get Info"
- Change Location from "iCloud" to "On My Mac"
Once you have checked the above, try subscribing again.