When trying to logon to Web Interface, you may see the following error, even when using valid credentials:

Please verify your user name and password and try logging on again. If you cannot log on, contact your help desk.

You will also see the following error in the URL:

CTX_MessageType=ERROR&CTX_MessageKey=GeneralCredentialsFailure

If you were logged on and refresh applications you may see the following error:

An error occurred while trying to enumerate your resources.

The Application Event log contains the following errors:

Log Name:      Application
Source:        Citrix Web Interface
Event ID:      30110
Level:         Error
Description:   Site path: C:\inetpub\wwwroot\Citrix\XenApp.
An error of type IMA with an error ID of 0x80000001 was reported from the Citrix XML Service at address . Depending on the server running the XML Service, more information may be available in the server's event log. This Citrix XML Service transaction failed, but the XML Service has not been removed from the list of active services.

Log Name:      Application
Source:        Citrix Web Interface
Event ID:      31003
Level:         Error
Description:   Site path: C:\inetpub\wwwroot\Citrix\XenApp.
All the Citrix XML Services configured for farm Percipient failed to respond to this XML Service transaction.
For specific information about this message, see the Web Interface documentation at http://support.citrix.com/proddocs/topic/web-interface-impington/wi-log-messages-event-ids-hardwick.html.

This issue was caused by a shortcut icon used from an executable (ConnectWise PSA).

When looking at the published application shortcut properties, the following error appears:

Unhandled exception has occured in a component in your application. If you click Continue, the application will ignore this and attempt to continue.

Details:

************** Exception Text **************
System.IO.EndOfStreamException: Unable to read beyond the end of the stream.
   at System.IO.__Error.EndOfFile()
   at System.IO.BinaryReader.FillBuffer(Int32 numBytes)
   at System.IO.BinaryReader.ReadInt32()
   at Citrix.IconConverter.Internal.IconDir.FromStream(Stream stream)
   at Citrix.IconConverter.ConvertIcon.ToImage(Stream data, Size size, Int16 bpp, ConversionMode conversionMode)
   at Citrix.IconConverter.ConvertIcon.ToImage(Byte[] data, Size size, Int16 bpp, ConversionMode conversionMode)
   at Citrix.CMI.PSE.Cmo.App.PropertyPages.ShortcutPresentationPage.ShowIcon()
   at Citrix.CMI.PSE.Cmo.App.PropertyPages.ShortcutPresentationPage.IconChanged()
   at Citrix.CMI.PSE.Cmo.App.PropertyPages.ShortcutPresentationPage.PageActivate(EditorNavigation navigation)
   at Citrix.CMI.CmiLib.CustomControls.PropertyEditor.PropertyDialog.ShowPage(IPropertyPage page)
   at Citrix.CMI.CmiLib.CustomControls.PropertyEditor.PropertyDialog.u_treeView_AfterSelect(Object sender, TreeViewEventArgs e)
   at System.Windows.Forms.TreeView.OnAfterSelect(TreeViewEventArgs e)
   at System.Windows.Forms.TreeView.TvnSelected(NMTREEVIEW* nmtv)
   at System.Windows.Forms.TreeView.WmNotify(Message& m)
   at System.Windows.Forms.TreeView.WndProc(Message& m)
   at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
   at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
   at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)

To resolve the issue, from Citrix Delivery Services Console:

- Select the application
- Right click and select Application Properties from the context menu
- Select Shortcut presentation
- Click Change icon
- Select the Choose an icon from a locally browsed file radio button
- Choose an icon source other than the application binary

Update: It appears a fix has now been released.
Hotfix DSCXACmd600W2K8R2X64004
http://support.citrix.com/article/CTX133017
"Application enumeration fails for applications that use a 32-bit PNG icon for the application shortcut. To address this issue in its entirety, you must install both a XenApp and a Delivery Services Console hotfix that contains Fix #259922."