How to view cloud file thumbnails in Windows File Explorer when enabling Qsync Client Space-Saving mode

Last modified date: 2026-08-11

Applicable Products

QTS, QuTS hero

Qsync Client for Windows v6.0.3 and later

Overview

In earlier versions of Qsync Client for Windows, files stored in Space-Saving mode appeared as placeholders in Windows File Explorer without thumbnail previews.

Starting from Qsync Client for Windows v6.0.3, thumbnail preview for cloud-only files is supported. Thumbnails are fetched in real time from your NAS, allowing you to visually identify files without downloading them.

Prerequisites

File Station thumbnail support must be enabled on your NAS. If you have not yet enabled thumbnails or want to know the details, see the following:

To enable thumbnail display, you must:

Install and activate CAYIN Media Viewer
Enable thumbnail generation in Multimedia Console
Enable multimedia support in File Station

You need extra setup for displaying the thumbnails of certain file formats.

Installing and Activating CAYIN Media Viewer

Go to App Center on your NAS.
Search for CAYIN Media Viewer.
Click Install.
After installation, open CAYIN Media Viewer.
Click Activate.

Enabling thumbnail generation in Multimedia Console

Install Multimedia Consoleif not already installed.
1. Open App Center.
2. Search for Multimedia Console.
  The Multimedia Console app appears in the search results.
3. Click Install.
Open Multimedia Console.
Go to Thumbnail Generation.
On the top right corner, click the toggle control.
Thumbnail generation is enabled and the toggle control label displays "Enabled".
Check the status of thumbnail generation and ensure that you have configured a schedule.

Important

Ensure that Multimedia Console is started and running normally on your system, otherwise thumbnails will not be generated for new files, and only previously generated thumbnails will be displayed.

Enable multimedia support in File Station

Open File Station.
On the top right corner click (more).
Click Settings.
The Options window appears.
Go to the Multimedia tab.
Click Support multimedia playback, streaming, and thumbnail display.
Click Close.

Tip

After configuring CAYIN Media Viewer, Multimedia Console, and File Station, you can restart your apps. Photo and video thumbnails on the NAS should now be displayed correctly.

Enabling thumbnails for HEVC videos (.mov) and HEIF images (.heic)

Thumbnail support for HEIF and HEVC files have the following requirements:

QTS 4.4.3 or later
Multimedia Console 1.1.3 or later

You also need a CAYIN Media Viewer license.

To purchase the license, go to QNAP Software Store.
After purchase, activate the the license.
For instructions on activating software licenses, see the License activation section of your system's User Guide (QTS4.5, QTS 5.1, QuTS hero 4.5, QuTS hero h5.1).
After activating the license, the system will automatically install CAYIN Media Viewer.
Important
Do not uninstall CAYIN Media Viewer from your system. Otherwise, thumbnail generation or display may not function correctly.

Enabling thumbnails for documents

Your NAS device must meet the following requirements for supporting document thumbnails:

64-bit (x86) or ARM64 CPU architecture
At least 2GB of memory

Install Qsirch if not installed already.
1. Open App Center.
2. Search for Qsirch.
3. Click Install.
4. Select an installation location.
5. Click OK.
  Qsirch is installed onto your system.
Ensure that Qsirch is running.
Warning
If Qsirch is not installed or started, you will only see previously generated document thumbnails and cannot generate new ones.
1. Open App Center.
2. Locate the Qsirch app.
3. If Qsirch is running normally, the Qsirch app icon will be displayed as following:
4. If Qsirch is not running, click the Start button:
Open File Station.
On the top right corner (more).
Click Settings.
The Options window appears.
Go to the Documents tab.
Select an option for Support Document Thumbnail Display:
1. Do not display: Thumbnails for documents will not be displayed.
2. Manually select a document to generate: Thumbnails for documents must be generated manually via the following steps.
  1. Open File Station.
  2. Locate a document file.
  3. Right click on the document.
  4. Click Thumbnail > Display Document Thumbnail.
  5. Automatically generate: Automatically generate thumbnails for document file formats selected from the list that appears below after selecting Automatically generate

Solution

Verify thumbnail display

Verify that Qsync Client for Windows is updated to v6.0.3 or later.
Open Windows File Explorer and navigate to your Qsync folder.
Switch to a thumbnail view, such as Large icons or Extra large icons.

Cloud-only files (indicated by a cloud icon) should now display thumbnails fetched in real time from your NAS.

Note

An active network connection to your QNAP NAS is required to display cloud file thumbnails.
Thumbnail loading speeds may vary depending on your network conditions.

Troubleshooting

If File Station thumbnail support is enabled and Qsync Client has been upgraded to v6.0.3 or later, but thumbnails are still not visible in Windows File Explorer, try the following steps:

Verify that Qsync Client is connected to your NAS.
Open Qsync Client for Windows and confirm that the connection status is shown as Connected.
Clear the Windows thumbnail cache.
1. Press Win + R, type cleanmgr, and click OK.
2. Select Thumbnails and click OK.
3. Wait for Disk Cleanup to complete.
4. Reopen Windows File Explorer and navigate to your Qsync folder to check whether thumbnails now display correctly.