|Product:||Internet Security and Acceleration Server|
|Source:||ISA Server H.323 Filter|
|Component:||ISA Server Services|
|Message:||The Firewall service encountered an illegal operation (runtime error R6025), in a pure virtual function. To resolve this error, remove recently installed application filters and restart the service.|
|One of the application filters is either corrupt or the filter contains a programming error.|
|After removing the application filter, restart the Firewall service. To to this, in the console tree of ISA Server Management, click Monitoring. In the details pane click the Services tab, and then select Microsoft Firewall service. In the Tasks tab, click Start Selected Services.
If this does not resolve the problem, contact the component vendor.