Usually, this happens because the default email account for calendar replies isn’t set up correctly, especially if it’s not an iCloud account, like Gmail or Outlook. Other reasons can be problems with calendar syncing, using an old iOS version, or issues with signing into your email account.
1. Turn Calendar Account Off and On
This method has worked for many users. The idea is to temporarily turn off the Calendar for the account you use, wait a few seconds, and then turn it back on.
2. Refresh Calendars Under iCloud
This method involves turning off the calendar in iCloud, waiting a little while, and then turning it back on. This forces your device to re-sync the calendar data.
3. Force Calendar App to Close
If the Calendar app is not working properly or isn’t responding, you can force close it. This removes it from your device’s memory and might clear out any issues with stuck data. Afterwards, you’ll need to open the app again.
