Autocreated Printers Do Not Appear in the Published Application When Establishing Multiple Session IDs on One Server with the Same User Account

Auto-created printers don’t appear in the published application when multiple session IDs on one server are established with the same user account. When a user establishes more than two sessions (two different session IDs) to one server, the published application in the first established session ID is NOT able to enumerate auto-created printers in the session.
This issue doesn’t happen when there are multiple sessions in seamless mode. By default, the seamless mode application has a session sharing function, so the multiple sessions in seamless mode will have the same session ID on one server.
Cause
Citrix Presentation Server 4.0 introduces the new auto-created printer architecture (dynamic session-private client printers), which is different from Presentation Server 3.0. With the new architecture, auto-created printers are managed by the same session ID. An application that refers registry entry directly in order to enumerate installed printers (e.g. Excel) may encounter this issue.
Reproduction Steps
Excel is used in this example:
1. Launch the published desktop by a certain user account.
2. Open Excel on the published desktop, then click File and select Print to confirm that auto-created printers are enumerated on this session. It should have no problem.
3. Launch Excel in seamless mode as a published application from the same server and with the same user account that you used in Step 1. Remember that this creates a separate session ID from the launched desktop.
4. After launching Excel in seamless mode, go back to the desktop. Open Excel on the desktop, and then click File and select Print.
5. The error message appears stating "Current printer is unavailable. Select another printer."
Resolution
Scenario 1
From one client device, multiple session IDs with the same account are established to one Presentation Server (Fig.1).
Use the same auto-created printer creation method (Legacy client printers) as Citrix Presentation Server 3.0 by applying Policy. The issue will be resolved because auto-created printers are created by the legacy method. Policy rule can be configured by the following:
• On the created Policy properties, select Printing > Client Printers > Legacy client printers and then select Create old-style client printers.

Fig.1 Multiple session IDs with the same account from one client device
Scenario 2
From different client devices, multiple session IDs with the same account are established to one Presentation Server (Fig.2).
There is no workaround for this situation. Citrix Presentation Server 4.0 introduces the new security context associated with session ID, so such applications which directly refer to the registry in order to enumerate printers are NOT able to enumerate printer information from the server in this situation. The resolution on Scenario 1 won’t resolve this issue. Refer to CTX106743 - Security Context of Auto-creation by Legacy Client Printers for the security settings for the new auto-created printers.

Fig.2 Multiple session IDs with the same account from different devices
Status
Citrix has escalated this issue to Microsoft. In lieu of a resolution to the problem from Microsoft, Citrix has released a workaround within Hotfix Rollup Pack 2.
CTX109307 - Hotfix Rollup Pack PSE400W2K3R02 - For Citrix Presentation Server 4.0, Citrix Access Essentials 1.0 and 1.5 for Windows Server 2003
CTX109306 - Hotfix Rollup Pack PSE400W2KR02 - For Citrix Presentation Server 4.0 for Windows 2000 Server
Caution! This fix requires you to edit the registry. Using Registry Editor incorrectly can cause serious problems that may require you to reinstall your operating system. Citrix cannot guarantee that problems resulting from the incorrect use of Registry Editor can be solved. Use Registry Editor at your own risk. Be sure to back up the registry before you edit it.
From the hotfix readme:
When a user launches multiple sessions to one server, the user's default printer in the first session may be lost and cannot be reset. This fix introduces support for a registry setting that adds the user’s name to the ACL of printers created in his or her sessions and allows that user to access printers from any of those sessions on the same server.
To enable this fix, you must set the following registry key:
Key: HKEY_LOCAL_MACHINE\SOFTWARE\Citrix\Print
Name: DefaultPrnFlags
Type: REG_DWORD
Data: 0x20000000

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