Blank window on Windows Server (WebView2)

Symptom

When you open the Polpo Desk client on Windows Server (e.g. Windows Server 2016 or 2019), the window stays blank, white or black; the connection ID and password never appear. The window may show only a status message, or nothing at all.

Likely causes

• Microsoft Edge WebView2 Runtime is not installed. The Polpo Desk client's interface is drawn with Microsoft's WebView2 component. Current versions of Windows 10 and 11 include it, but on Windows Server 2016/2019 and some older Windows 10 installations it is not installed.
• Servers without a graphics card (GPU) and RDP sessions. Without hardware acceleration, WebView2 can draw the window black.
• An old client version. Old versions don't detect that WebView2 is missing, or can't download it because of Windows Server's Internet Explorer security settings.

How to fix it

1. Accept the WebView2 installation offered by the client

If WebView2 is missing, the current client detects this at start-up and asks you:

1. Click Yes in the dialog.
2. The client downloads Microsoft's official installer (about 2 MB), verifies Microsoft's signature and installs the component silently. Progress is shown in the window.
3. Because the installer downloads the actual component from Microsoft, this can take a few minutes depending on your internet speed. When it finishes, the interface loads on its own.

If you click No, the window tells you to install the component and reopen Polpo Desk.

2. Install WebView2 manually

If the automatic installation fails, the window shows a "Could not download WebView2" or "WebView2 could not be installed" message. In that case:

1. Download the "Evergreen" installer of Microsoft Edge WebView2 Runtime from Microsoft's website (if you can't download it on the server, download it on another computer and copy it over).
2. Run the installer as an administrator.
3. Close and reopen Polpo Desk.

3. Update the client

If you're on an old version, the missing WebView2 may not be detected, or the download may be blocked by Internet Explorer Enhanced Security Configuration (IE ESC) on Windows Server. Version 0.9.106 and later perform this download with a method that IE ESC doesn't affect. Get the latest client from the Downloads page; for update problems, see Update fails with "Could not reach the server".

4. Servers without a GPU and RDP sessions

When the current client detects that it is running on Windows Server or in an RDP session, it automatically draws its interface without hardware acceleration (in software). Since the interface is small, this doesn't affect performance. If the window still stays black, update the client.

The client also retries on its own when the interface can't be loaded or the WebView2 process crashes. If the window fixes itself after a while, this mechanism is at work.

5. Window stays black when opened from the tray

If the client starts in the system tray when the computer starts and the window stays black when you open it from the tray, this was fixed in version 0.9.100. Update your client.

When to contact support

If WebView2 is installed and the client is up to date but the window is still blank, contact us. Attach the %TEMP%\polpodesk-native.log file to your request; lines starting with webview and webview2-setup show the cause. To open a support request, see Creating and tracking a support request; for supported systems, see System requirements and network settings.