I was able to solve the problem on both my iPhone X and iPad. The error was being generate by my Exchange account. I went to Settings->Accounts & Passwords->[exchange account] . I then switched off the calendar, chose to delete it from my phone, and finally switched it back on. No problems since on either device.
unfortunately this did not solve the issue, any other suggestions?
Perfect thank you worked - was becoming very frustrating cheers I am is 12.01
This worked for me. Thanks!
I have this happening now, new XR, and the suggested solution does not work, any other ideas?
Nope, still there. Turned them off, turned off and restarted the phone, and this was my welcome back screen.
Checking all the calendars in my Accounts and shutting off the one causing the problem helped. The “most helpful” solution of shutting the iCloud calendar was not my issue and didn’t help.
This is is still an issue in iOS 11.4.1. Hopefully Apple has this fixed by iOS 12 coming soon. If not Apple, Exchange and Gmail need to check their calendars in the newest iOS and provide updates. It’s ridiculous this issue has been going on so long. My issue just started yesterday. No recent updates or apps or anything. Happened on all my devices. Needed a fix ASAP!
Thank you r_a10013!
Having same issue as well. Have tried turning off iCloud multiple times and continue to get error several times a day.
So glad you were able to fix the issue...must be for new iphones as it still is not working for me and becomes more annoying each day.
Thanks for feedback, its resolved my issue by turn off and on from calendar on my exchange account .
Much appriciated .
Thanks
This started happening the day I shared my O365 calendar and two members of my team shared theirs with me... aggravating issue that needs to be resolved!
Calendar Invitation Error
