Vanilla WPF application hangs on one customer's machine

Question

At a customer, one of our WPF applications started to hang. When trying to reproduce the problem with a minimal working example, I discovered that even the most basic (non-trivial) WPF application will hang on that machine.

Example A: Create a new C# WPF project in Visual Studio 2008. Change nothing, compile it and run it on the customer's machine. It will run.

Example B: Take Example A, and add a TextBlock to the main form Window1:

<Window ...>
    <Grid>
        <TextBlock>Test</TextBlock>
    </Grid>
</Window>

Compile the application and run it on the customer's machine. It will hang: The title bar and the window border is visible, the inside is transparent and the window does not react to anything (cannot be moved or closed). The application must be shut down using the task manager.

Obviously, this customer's WPF is broken. Is this a known issue, i.e., has anyone encountered it before and already knows how to solve it (e.g. reinstall .net 3.5 SP1, etc.)?

The development machine is W7SP1, the customer's machine is XP (probably SP3, didn't check).

Answer 1

Check out Tom Dudfield's instructions to clear the WPF font cache. It's worked for me for several users.