2020-12-15 12:41:08,462 [YDAWBH120][Thread:65][FATAL] DotNetNuke.Framework.PageBase - An error has occurred while loading page.
System.NullReferenceException: Object reference not set to an instance of an object.
   at DotNetNuke.Entities.Portals.PortalSettingsController.ConfigureActiveTab(PortalSettings portalSettings)
   at DotNetNuke.Framework.DefaultPage.InitializePage()
   at DotNetNuke.Framework.DefaultPage.OnInit(EventArgs e)
   at System.Web.UI.Control.InitRecursive(Control namingContainer)
   at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
2020-12-15 12:41:08,603 [YDAWBH120][Thread:65][ERROR] DotNetNuke.Services.Exceptions.Exceptions - ~/Default.aspx?error=An unexpected error has occurred&content=0
System.NullReferenceException: Object reference not set to an instance of an object.
   at DotNetNuke.Entities.Portals.PortalSettingsController.ConfigureActiveTab(PortalSettings portalSettings)
   at DotNetNuke.Framework.DefaultPage.InitializePage()
   at DotNetNuke.Framework.DefaultPage.OnInit(EventArgs e)
   at System.Web.UI.Control.InitRecursive(Control namingContainer)
   at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
2020-12-15 20:10:01,650 [YDAWBH120][Thread:79][ERROR] DotNetNuke.UI.WebControls.DNNListEditControl - System.FormatException: Input string was not in a correct format.
   at System.Number.StringToNumber(String str, NumberStyles options, NumberBuffer& number, NumberFormatInfo info, Boolean parseDecimal)
   at System.Number.ParseInt32(String s, NumberStyles style, NumberFormatInfo info)
   at System.String.System.IConvertible.ToInt32(IFormatProvider provider)
   at System.Convert.ToInt32(Object value)
   at DotNetNuke.UI.WebControls.DNNListEditControl.get_OldIntegerValue()