Description
When using Microsoft operating system Windows Server 2003 SP1 or SP2, there can be rare cases of blocking on the OS clients if two clients (one after another) access the same runtime screen (*.pdl). Operation of the OS client is disrupted (hour glass) during this blocking.
The error that leads to this behavior is in the Kerberos ticket handling of the Microsoft operating system Windows Server 2003.

KB 943459 has been updated by Microsoft for Windows Server 2003 SP2 with KB 971468 (also available via WSUS).

More detailed information about Microsoft Patches is available in the entries below.

• "Which Microsoft Security Patches have been tested for compatibility with SIMATIC WinCC?" in Entry ID: 18752994
• "Which Microsoft Security Patches have been tested for compatibility with SIMATIC PCS 7?" in Entry ID: 18490004

A correction is provided by Microsoft in KB 943459 and KB 971468 at the following links.

We therefore recommend that you install Microsoft Patch KB 943459 or KB971468 as soon as possible.

German Link
http://support.microsoft.com/kb/943459/de

http://support.microsoft.com/kb/971468/de

English link
http://support.microsoft.com/kb/943459/en-us

http://support.microsoft.com/kb/971468/en-us

Installation notes
You have to restart the computer after installing this hotfix.
Close all SIMATIC applications beforehand.

Note
Patch KB 943459 modifies the following code in the Registry: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\LanmanServer\Parameters OplockBreakWait. Do not change the default time of 35 seconds set in the parameter OplockBreakWait.