Parallels Client Modern UI hangs or crashes on launch after installing a Windows update

Symptoms

After installing a recent Windows update, the Parallels Client Modern UI may hang and subsequently crash when launching ParallelsClient.exe. The Classic UI is not affected by this issue.

This issue affects the following versions of Parallels Client for Windows:

• v21.1.1
• v21.2.0

Cause

Applications that depend on XAML packages - such as the Parallels Client Modern UI - may fail to start if XAML packages are not registered in time after certain Windows updates are installed.

The issue was introduced with the following Windows update:

• KB5095093 - June 23, 2026 (OS Builds 26200.8737 and 26100.8737) Preview

This is a known Microsoft issue affecting Explorer, the Start menu, and other XAML-dependent applications. For more information, see the Microsoft article: KB5072911 - Explorer, the Start menu, and other XAML-dependent apps might not start or close unexpectedly.

Resolution

Install the Windows update that contains the fix described in Microsoft article KB5072911, then restart the machine.

Workaround (until the fix is installed): Switch Parallels Client to the Classic UI, which is not affected by this issue.