What is one common error when using iCloud that can lead to duplicate calendars?

When using iCloud, syncing with multiple accounts is a common error that can lead to the creation of duplicate calendars. This situation often arises when a user has multiple iCloud accounts or has also set up other service accounts, such as Google or Microsoft Exchange, for calendar synchronization. When these accounts are connected to the same device or application, it can result in overlaps and duplications because the same calendar information may be synced from more than one source. This can clutter the calendar view and create confusion as appointments and events appear multiple times.

In contrast, incorrect password entry typically leads to failed logins or access issues rather than duplicating calendars. Not updating to the latest iOS could impair functionality in various ways but is less likely to be the direct cause of duplicate calendars themselves. Similarly, using non-Apple devices might affect the overall user experience or available features, but it doesn't inherently cause calendar duplication as the syncing mechanisms are still structured around account connections rather than the device type.