Login language issue

Hello,

I am running into an issue whenever a user tries to log in to our site (Sitefinity 5.4) when the user has Arabic set as the default language in his browser. The stack trace is:

System.FormatException: String was not recognized as a valid DateTime.   at System.DateTimeParse.Parse(String s, DateTimeFormatInfo dtfi, DateTimeStyles styles)   at System.DateTime.Parse(String s, IFormatProvider provider, DateTimeStyles styles)   at Telerik.Sitefinity.Security.Claims.ClaimsResolver.ParseSitefinityClaims(ClaimCollection claims, String& tokenId, Guid& userId, String& name, String& membership, DateTime& issueDate, DateTime& lastLoginDate, IEnumerable`1& roles, Boolean& isUnrestricted, Boolean& isBackendUser)   at Telerik.Sitefinity.Security.Claims.ClaimsIdentityProxy.Initialize(IClaimsIdentity identity)   at Telerik.Sitefinity.Security.Claims.ClaimsPrincipalProxy.Initialize(IClaimsPrincipal principal, String primaryIdentityLabel)   at Telerik.Sitefinity.Security.Claims.ClaimsResolver.GetPrincipal(HttpContext context)   at Telerik.Sitefinity.Security.Claims.SitefinityClaimsAuthenticationModule.OnPostAuthenticateRequest(Object sender, EventArgs e)   at System.Web.HttpApplication.SyncEventExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()   at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)

Does anyone know of a fix for this, other than setting another language as default?

Hello Josh,

This issue should be fixed in Sitefinity 6.0 release. Here is a link to the release notes:
http://www.sitefinity.com/developer-network/forums/general-discussions-/sitefinity-6-0-released

And here is an excerpt from 6.0 release notes:
Authentication
Unable to authenticate when the culture is set to "ar" (Arabic)

We recommend that you upgrade your project following the official upgrade path and instructions on how to upgrade from one version to another. Here is a link to our documentation page on upgrades:
http://www.sitefinity.com/documentation/documentationarticles/installation-and-administration-guide/upgrade 
Please, follow the instructions since there are changes that are needed to be done in web.config file in order to upgrade correct your project.