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Windows 10 Phone issue Lumia 1520.
Latest update Mail and Calendar 16006.11001.20083.0
This update came right after the Microsoft Store update: 11810.1001.12.0.
Mail and Calendar no longer starts. After a short flash screen the app crashed back to the main screen. Tried restart and soft reset.
App got updated today 07-11-2018. This morning before the update it worked fine.
Found multiple users with this problem on Appraisin website.