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.
Thanks much for your help, it worked!
This did not help. In fact I keep getting interrupted with the pop up that is debilitating.
I had the same problem
Thank you for your suggestions! It helped and the back up on my calendar didn’t take 20-40 mins. It only took about 5 mins!
Thank you! Tried multiple other recommendations, and this was the one that helped.
I had this problem a couple of months ago, did the suggested fix and now it is back again .....
Any idea WHY it keeps happening ?
I tried the other suggested solutions and they did not work for me. This solution did work.
the solution proposed by mayerzd worked for me!!! many thanks!!!
iPhone 7, iOS 11.4
I have the same issue , any ideas for iPhone 6
THANK YOU! This fixed this!!!!!!!!!
Issue was solved with the suggestions from your end guys
Thanks
Thank you. This worked for me as well. I have been trying to figure this out for a while. Much appreciated.
This absolutely worked perfectly for me! thanks!
This is the correct fix for my Exchange account on my IPad. I don’t believe you even need to restart your device.
I’m having the exact same issue and even with the calendar, contacts and reminders turned off in iCloud settings the issue continues. Brand new phone - come on Apple resolve this issue.
Calendar Invitation Error
