I am trying to upgrade a DNN 4.5.5 site to 4.6.2 on the way to upgrading to 4.9.1 but am running into a problem when I try to login. I get the following error:

formatException: Input string was not in a correct format.]
   System.Number.StringToNumber(String str, NumberStyles options, NumberBuffer& number, NumberformatInfo info, Boolean parseDecimal) +2755599
   System.Number.ParseInt32(String s, NumberStyles style, NumberformatInfo info) +112
   DotNetNuke.Entities.Users.UserProfile.get_TimeZone() +39
   DotNetNuke.Entities.Users.UserTime.get_ClientToServerTimeZoneFactor() +32
   DotNetNuke.Entities.Users.UserTime.get_CurrentUserTime() +145
   DotNetNuke.UI.Skins.Controls.CurrentDate.Page_Load(Object sender, EventArgs e) +196
   System.Web.UI.Control.OnLoad(EventArgs e) +99
   System.Web.UI.Control.LoadRecursive() +47
   System.Web.UI.Control.LoadRecursive() +131
   System.Web.UI.Control.LoadRecursive() +131
   System.Web.UI.Control.LoadRecursive() +131
   System.Web.UI.Control.LoadRecursive() +131
   System.Web.UI.Control.LoadRecursive() +131
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +1436

[PageLoadException: Input string was not in a correct format.]
   DotNetNuke.Services.Exceptions.Exceptions.ProcessPageLoadException(Exception exc, String URL) +376
   DotNetNuke.Framework.PageBase.Page_Error(Object Source, EventArgs e) +483
   System.Web.UI.TemplateControl.OnError(EventArgs e) +2085460
   System.Web.UI.Page.HandleError(Exception e) +71
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +7341
   System.Web.UI.Page.ProcessRequest(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +213
   System.Web.UI.Page.ProcessRequest() +86
   System.Web.UI.Page.ProcessRequestWithNoAssert(HttpContext context) +18
   System.Web.UI.Page.ProcessRequest(HttpContext context) +49
   ASP.default_aspx.ProcessRequest(HttpContext context) +4
   System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +358
   System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +64

Do you happen to know what is going wrong here? I can successfully display the website in the browser and most everything seems to work with the exception that I cannot log in which, of course. is a show stopper!

Thanks for any help you can give!

Frank

Sebastian,

I have checked the userprofile table and all users appear to have a valid time zone. I have had no success in fixing this issue and have rolled back to 4.5.5 twice and reinstalled 4.6.2 as an interim upgrade but now I cannot sign in with any signon. After upgrading directly from 4.5.5 to 4.9.2 at least I could signon as 'Admin'.

I am wondering what the difference in the 4.6.2. upgrade (and also 4.9.2) that causes this error but not in 4.5.5. Would you have any othe suggestions for tracking down the culprit that is causing this issue?

I am about to rollback to 4.5.5 once again so my users can log in. Any help is greatly appreciated!

Thanks!

Tugboat