I know I'd be lost without my calendar, so I understand the need to make sure you can sync it with your computer when you want to. Let's tackle this together and get to the bottom of this data message you're receiving so you can sync appropriately. I also want to send a shout-out to boringusername and Ann154 since they asked a couple of great questions. On top of their questions, I have a couple more details I'd like to gather from you.
Do you have any other Email accounts? If so, how are they working from a data/syncing perspective? Has the Microsoft calendar app worked at all in the past for you, or is this the first time using it? Also, for troubleshooting purposes, what is the make and model of your device?
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