Windows 10: missing calendar

Hello! All of a sudden my calendar has disappeared from my available apps. When I click on the date in the bottom right-hand corner the calendar small one appears, but I can't click on to make an appointment or view appointments.

:)

 

Calendar events missing in App

Hello,

One possible reason why you lost the events you set up 12 days in the past and 13 days in the future is due to some recent changes you made either with the account you signed in, or in the Calendar app settings. To help you restore the missing events in
your Calendar App, kindly supplement us with more information by answering these questions:

• Were there any changes made with the account you signed in, or in the Calendar app settings prior to the issue?
  
• When did you notice that there are missing events?
• Did this issue happen before?
• What are the steps that you have done in an attempt to resolve the issue?

We look forward to your prompt reply.

 

Why did the startup window get cleared?

I didn't missed any step, the list was gone and gone , even after using lot of programs the programs were not listed in that list.

 

Calendar events missing in App

1) No

2) 6/9/2017

3) No

4) a) Close Calendar and re-open. b) Wait a few minutes. c)Reboot computer and try again the next day. d) Ask for Microsoft for help on this forum.