When you sign out of Extradium, you might run into an issue whereby the following message is displayed or logged in the SharePoint ULS log file:


 

Exception of type 'System.ArgumentException' was thrown. Parameter name: encodedValue at
Microsoft.SharePoint.Administration.Claims.SPClaimEncodingManager.DecodeClaimFromFormsSuffix(System.String)
Microsoft.SharePoint.Administration.Claims.SPClaimProviderManager.GetProviderUserKey(Microsoft.IdentityModel.Claims.IClaimsIdentity, System.String)
Microsoft.SharePoint.Administration.Claims.SPClaimProviderManager.GetProviderUserKey(System.String)
Microsoft.SharePoint.Utilities.SPUtility.GetFullUserKeyFromLoginName(System.String)
Microsoft.SharePoint.ApplicationRuntime.SPHeaderManager.AddIsapiHeaders(System.Web.HttpContext, System.String, System.Collections.Specialized.NameValueCollection)
Microsoft.SharePoint.ApplicationRuntime.SPRequestModule.PreRequestExecuteAppHandler(System.Object, System.EventArgs)

 

This is a well-known issue when using mixed mode authentication with Windows authentication and Forms-based authentication, as mentioned in the following Microsoft KB article: https://support.microsoft.com/en-us/kb/2988406


To resolve this issue, replace the Sign Out link with the Sign-in As Different User link for all web front end-servers on the SharePoint farm by following these steps:

  1. In the following folder, open the welcome.ascx file in a text editor such as notepad:

    C:\Program Files\Common Files\Microsoft Shared\Web Server Extensions\15\TEMPLATE\CONTROLTEMPLATES

  2. Replace the old text with the new text as follows:
    Old text

    <SharePoint:MenuItemTemplate runat="server" id="ID_Logout" Text="<%$Resources:wss,personalactions_logout%>" Description="<%$Resources:wss,personalactions_logoutdescription%>" MenuGroupId="100" Sequence="400" UseShortId="true" />

    New text

    <SharePoint:MenuItemTemplate runat="server" ID="ID_LoginAsDifferentUser" Text="<%$Resources:wss,personalactions_loginasdifferentuser%>"  Description="<%$Resources:wss,personalactions_loginasdifferentuserdescription%>"  MenuGroupId="100"  Sequence="400"  UseShortId="true"  />


Important note: The text and description attributes are changed to mimic the logoff button, but you really only have to change the id value (from ID_Logout to ID_LoginAsDifferentUser) of the control.