Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
Hello Zaraid,
Good morning!
Thank you for publishing in Microsoft Community. We are happy to help you.
It sounds like you're experiencing a recurring error message when trying to respond to a Teams calendar invite on your iPhone. The message, "Your response to the invitation cannot be sent," keeps popping up,
There can be different reasons for this. Either the Calendar application is not synchronized correctly or there is some old cache stuck in the phone’s memory that needs to be cleared.
Before you proceed make sure that the Calendar application is up-to-date. Make sure you have the latest version of Microsoft Teams installed. For Teams hardware requirements on mobile: See Hardware requirements for Microsoft Teams - Microsoft Teams | Microsoft Learn.
However, to narrow down the issue and provide a right guidance, we need more details from you, please provide us with the following information. Thank you.
1-Make sure that your password for the email account on the iPhone that is showing the calendar error is current.
Additionally turn any calendar accounts off and on again. To do this, open Settings > Calendar > Accounts. Choose any accounts here that you use your Calendar with and turn Calendar off and then on again i mean go to setting Mail > Account> open the account that is has the affected calendar << Hit the slider button to disable calendar. Wait for it to disable then hit the button for it to enable. and restart your iPhone to check the issue
2-Please try Turn off the calendar on your iCloud itself for a few seconds and then Turn it On again. This will force the device to resynchronize the Calendar app data.
Go to the iPhone Settings and tap on your name
Now tap on the iCloud icon and Toggle off the Calendars
Wait for a few seconds and then turn it back On
3-If the issue still persist try to clear the teams cache on your iOS and uninstall , re-install the teams app to check the issue If the issue still persist the issue might be related to the some old cache stuck in the phone’s memory that needs to be cleared in your Iphone so let me know.We look forward to your reply. We will continue to assist you based on the information you provide. I sincerely appreciate your patience and cooperation.SincerelyEben Ezer Tres | Microsoft Community Moderator