SharePoint Shine

< BigCalendar selectable events ={ this . state . events } defaultDate ={ new Date ( 2019 , 2 , 19 )} Culture='ja' style ={{ height : "100vh" }} />

Solution - Don't Create a page with the name "default.aspx" in Site Pages Library in SharePoint online,  Note: I have Renamed the default.aspx with home1 for me my issue got fixed.