Issue between IIS on Window Server 2019 and IIS on Windows Server 2025

Hello,

With Wisej 3.5, I developed a test application using the ‘Wisej.NET Web Page Application (.NET Framework)’ template.
The application has a page with a label. When the page loads, a message with the following code is displayed:

Private Sub Page1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
Wisej.Web.MessageBox.Show(“HELLO”, “Info Message”, MessageBoxButtons.OK, MessageBoxIcon.Information)
End Sub
After the message, the page displays the label.

Everything works correctly if I deploy the application to IIS on a machine with Windows Server 2019. However, if I do the same on a machine with Windows Server 2025, nothing appears on the page after the message (the page remains blank).

If I instead delete the message:
Private Sub Page1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
‘Wisej.Web.MessageBox.Show(“HELLO”, “Info Message”, MessageBoxButtons.OK, MessageBoxIcon.Information)
End Sub
The label displays correctly on both servers.
IIS is configured the same on both servers.
Any suggestions?

I’ve attached the test application.

Thanks in advance