JSI Tip 1392. Event Viewer hangs or won't start after saving a Filter?.

If the registry entry that contains the Filter is damaged, the subject behavior will occur.

Use Regedt32 to navigate to:

HKEY_CURRENT_USER\Software\Microsoft\Windows NT\Currentversion\Network\Event Viewer

In the right hand pane, double-click the Filter and Find Value Names and clear the string values.