Calendar Invitation pop-up error has iphone locked
I cannot get to me Settings to turn off/delete my calendar. I cannot restart/shut down my iphone because the pop-up error basically has my phone locked on that screen. I click OK and it just keeps coming back. Most times in the past, after I click OK a few times, that pop-up goes away for a while, but today I cannot get it to go away and essentially cannot use my phone at all. I went to iCloud.com and removed my work calendar, which is what I usually need to do to get this to stop. I had it off for a long time and decided to turn it back on yesterday, and now I'm sorry I did. I used to be able to have my work calendar on my iphone and view upcoming meetings from my phone, but I can no longer do that, and it's very inconvenient. More importantly, I just want to be able to turn off that calendar (or remove it for good) and use my phone again. Do I also have to remove my personal calendar? I'm going to try that now. Help!!
iPhone XR, iOS 13