PDF XChange Forum

I recently purchased PDF X-Change Pro 250 users for my Citrix XenApp 4.5 farm and am experiencing a serious issue that is greatly affecting productivity that must be resolved ASAP. We use a published desktop where the application suite has been installed (Viewer, Tools, Office Add-in, etc).

Users have been reporting session "freezes" which cause all running applications within the published desktop to become unusable. The shell/explorer becomes unresponsive and, therefore, they are unable to log off the system to exit the session. Administratively terminating all processes in use does not recover the session (must be done by an administrator logged into the console of the server where the user is logged into the published desktop as the user cannot access the task manager or anything else for that matter). The only method of ending the session is by logging it off using the Citrix Access Management Console. There are 70 users which access the farm but only 15% experience the issue, however, each day we have reports of additional users that do.

The issue seems to occur intermittently and can occur to the same user several times per day. Obviously this becomes very disruptive to both the user and our IT support as only a support personnel can log the user off so that they can log back in and continue working (a new session).

Until today, I was unable to reproduce this issue. It only happens when using programs in the Office 2007 Standard suite, or the PDF XChange Viewer. It often occurs when a user attempts to attach a file (not necessarily a PDF) to an email in Outlook. The process I've been able to reproduce the problem is as follows:

Open a PDF with the viewer via windows explorer.
Right-click the minimised explorer window on the taskbar, the session immediately locks up.
The viewer is still responsive, however, all applications and the shell/session outside the viewer become completely unresponsive. I suspect the users who experience random crashes while using the office suite may be related to the PDF Xchange office plugins.

Some notes on my environment:

Citrix XenApp 4.5 R02, 4 servers in farm, issue occurs on all servers.
Windows Server 2003 32 bit.
Published desktop.
Mix of thin client and desktops.
Issue started immediately after installing PDF XChange Pro 4.0 (latest release 4.0180, installed using the 32 bit MSI installer in Terminal Services installation mode).

Your immediate attention to this issue is greatly appreciated.

Hi,

we are looking into urgently and will come back if further info is required - thanks for your patience.

I suspect the problem maybe with our Shell Extension (build 2.0.50 of SE can lockup Windows Explorer on some circumstances).

Please try to unregister SE and see if the problem still exists. To unregister, please run

regsvr32 /u "c:\Program Files\Tracker Software\Shell Extensions\XCShInfo.dll"

And please let me know if this has solved the issue.

Thanks for the prompt reply. Your suggestion sounds promising.

Can the unregistration be done while users are logged into the Citrix servers? Do I need to switch to installation mode or leave it in execute mode?

I have unregistered the dll as indicated on all Citrix servers while users are logged in.

I was then able to repeat the process I outlined that consistently reproduced the shell lock up and it did not occur. This is great news.

However, I have since had another user report that when sending email they experienced a lock up, so I'm concerened we may have more than one issue we're dealing with.

Please advise.

Please advise the email client in use (Outlook 2007 again ?) - this is not a known issue and I suspect this may be a 'false' alarm in relation to PDF-XChange at least.

I suggest we take this one step at a time - and wait to see if this latest issue is replicated and hopefully a more detailed report from the user can provide a clue as to the cause and steps can then be taken to resolve - if the cause is after all one of our components.

John.

Yes we use Outlook 2007. I believe the additional report I had received following de-registering the shell extension was, as you've suggested, a false alarm. The initial issue seems to have been resolved.

Can you please let me know which functionality is lost by disabling the shell extension?

Thanks for all your help thus far.

The Shell extension provides a few helper tools to the OS so it can:
- generate thumbnail previews
- allows full text search inside PDF documents from Windows Explorer
- integrates a preview handler in Outlook
and a few similar tasks, nothing that should influence your ability to use the main functionalities in our products.

Best,
Stefan

New build, which should be released later today, has a fix for this SE issue.