Why I cannot open Apple Native App？

Apple Native Apps, including Calendar, Map, TV, Voice Memo, and many others, come with iPads.  Sometimes, they are not managed by MDM or have a problem to open for use.  In this case, you may consider:

1. Delete the Apps manually from the iPads (you may need to remove profiles “Disable AppStore/Apps Install/Remove”, “Disallow App Removal” and unset Homescreen Layout)
2. VPP Install the Apps again