Citrix Workspace App: Unresponsive Invisible Screen Region Blocking Mouse Clicks in DaaS VDI Session

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Article ID: CTX696935

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Updated On:

Description

Symptoms & Scope

  • Symptom: Mouse clicks fail to register in a specific region (typically top-left of the screen, sometimes visible as a black box) inside the session window.

  • Trigger: Highlighting text and dragging the cursor across or beyond the Citrix session window boundary.

  • Scope:

    • Affects Citrix DaaS VDI Sessions using Citrix Workspace App (including versions 2507, 2507 LTSR CU2, and 2511) on VDA versions 2507 and 2507 CU1 hosted on Azure.

    • Occurs in both windowed and full-screen modes.

    • Does not occur when using the Citrix HTML5 Client (browser-based access).

  • Logs Observation: Client logs repeatedly report: ccdialog | Error | WndProc RefreshConnList failed with error code: 20

Resolution

Primary Fix

This is a known client-side input-handling defect where mouse capture fails to reset properly after crossing session boundaries.

  • Permanent Resolution: Apply Private Fix CVADHELP-31919 supplied by Citrix Technical Support. Contact Citrix Support and reference hotfix ID CVADHELP-31919 to obtain the patch for your deployment.

Temporary Workarounds & Next Steps

If immediate patch deployment is not feasible, use the following workarounds to mitigate the issue:

  1. Session Reconnect: Disconnect and reconnect the affected Citrix session to restore full mouse interaction across the screen.

  2. Keyboard Selection: Use keyboard navigation (e.g., Shift + Arrow keys) instead of mouse-click-and-drag to select and highlight text.

  3. Cursor Boundary Precaution: Avoid dragging the mouse pointer past the edges of the Citrix Desktop Viewer window during drag-select operations.

  4. Use HTML5 Client: Fall back to browser-based access via the Citrix HTML5 receiver where the input capture bug does not manifest.

Issue/Introduction

In Citrix DaaS environments using Workspace App, dragging the mouse cursor past the session window boundary while highlighting text causes a region of the screen to become unresponsive to mouse clicks. This issue is caused by a client-side input capture defect, for which a private fix (CVADHELP-31919) is available.

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