Login to Forum as admin and Host Adminstration, Host Settings and just clicking on Save Settings button results in error. Trying to set Require User Login, or Server Time Zone Correction

Server Error in '/forum' Application

A potentially dangerous Request.Form value was detected from the client (forum$ctl02$HostSettingsTabs$View7$UserBox="

[HttpRequestValidationException (0x80004005): A potentially dangerous Request.Form value was detected from the client (forum$ctl02$HostSettingsTabs$View7$UserBox="

System.Web.HttpRequest.ValidateString(String value, String collectionKey, RequestValidationSource requestCollection) +11483972
System.Web.HttpRequest.ValidateNameValueCollection(NameValueCollection nvc, RequestValidationSource requestCollection) +82
System.Web.HttpRequest.get_Form() +212
System.Web.HttpRequest.get_HasForm() +11486708
System.Web.UI.Page.GetCollectionBasedOnMethod(Boolean dontReturnNull) +141
System.Web.UI.Page.DeterminePostBackMode() +100
System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +11439106
System.Web.UI.Page.ProcessRequest(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +11438622
System.Web.UI.Page.ProcessRequest() +269
System.Web.UI.Page.ProcessRequest(HttpContext context) +167
ASP.default_aspx.ProcessRequest(HttpContext context) in c:\Windows\Microsoft.NET\Framework64\v4.0.30319\Temporary ASP.NET Files\forum\3a20a4a6\6b382209\App_Web_xooiczrc.3.cs:0
System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +625
System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +270