Calendar not holding information

When I type in an appt time on a certain date/time etc.  and click save, it saves for about 5 seconds and then goes blank.

Hi Ray,
what calendar account does this happen on? Or is it a shared calendar? Do you have permission to edit the events inside this calendar?

Regards,
Olivia

I have the free license and I am the only user of this calendar.  If by editing events you mean adding and changing appt times dates etc.  Yes, I have been able to do this.  I just upgraded to Windows 10 and am wondering if that has something to do with it.  Thanks for your help.