topic Re: max2027 crashes when using maxscript to display a WPF window in 3ds Max Programming Forum

max2027 crashes when using maxscript to display a WPF window

lgedZV4XV — Sat, 11 Apr 2026 21:59:50 GMT

In 3dsmax 2027, any WPF window created with maxscript will crash when show it, for example:

(dotnetObject "System.Windows.Window").Show()

Re: max2027 crashes when using maxscript to display a WPF window

spacefrog_ — Sun, 12 Apr 2026 04:10:19 GMT

Can confirm the crash ( Works in 2026 )

just for completeness, also happens if you do something like

w= dotnetObject "System.Windows.Window" w.Show()

w is a valid window object and one can set properties etc ...

Re: max2027 crashes when using maxscript to display a WPF window

lgedZV4XV — Sun, 12 Apr 2026 07:12:24 GMT

It works fine in max2010-2026, only crashs in max2027..

Re: max2027 crashes when using maxscript to display a WPF window

A娘 — Sun, 12 Apr 2026 13:44:25 GMT

only dynamical wpf window throw error , when write as xaml in a dll , run normal

Re: max2027 crashes when using maxscript to display a WPF window

lgedZV4XV — Mon, 13 Apr 2026 09:31:20 GMT

If you show the window in maxscript, the wpf window written in the dll will also crash.

w = dotnetObject "YourDll.YourWindow" w.Show() --Crash! w = (dotnetClass "YourDll.YourWindow").GetWindow() w.Show() --Crash!

Only WPF dlls written in pure c# that don't interact with maxscript don't crash, but there is a lot of interaction in many projects. is Autodesk aware of this problem?

Re: max2027 crashes when using maxscript to display a WPF window

MartinBeh — Wed, 15 Apr 2026 17:19:11 GMT

FYI, the bug has been reported to the team.

Re: max2027 crashes when using maxscript to display a WPF window

ads_decatae — Fri, 17 Apr 2026 15:11:07 GMT

Thanks again for that @MartinBeh !

Re: max2027 crashes when using maxscript to display a WPF window

lgedZV4XV — Thu, 07 May 2026 01:07:52 GMT

Is there any way to fix this bug?

Re: max2027 crashes when using maxscript to display a WPF window

maxencoding — Thu, 14 May 2026 03:39:27 GMT

I've been following this issue closely, refreshing the page almost daily for new replies, hoping to find out when it will be fixed or if there are any temporary solutions. @MartinBeh

Re: max2027 crashes when using maxscript to display a WPF window

MartinBeh — Fri, 15 May 2026 08:11:51 GMT

All I can say is that is has been logged into the official bug report database - not idea when/how/for which version of 3ds Max this will be fixed, sorry.

Maybe one of the more dotNet savvy folks around here knows a workaround until there is an update that fixes this for good?

Re: max2027 crashes when using maxscript to display a WPF window

lgedZV4XV — Sat, 16 May 2026 22:14:43 GMT

Thanks all the same!

Re: max2027 crashes when using maxscript to display a WPF window

denisT.MaxDoctor — Mon, 18 May 2026 16:45:04 GMT

If you are reporting a crash, please provide a bit more detail about how it happens.

Does it crash immediately on Show(), after the window appears, or when the window is closed?

Also, are there any error messages or outputs shown anywhere:
- MAXScript Listener
- Autodesk crash dialog (CER)
- any other console or log output

Right now most reports only say “it crashes”, but without the actual error output it is difficult to understand whether this is a WPF issue, a .NET hosting issue, or something else.

Re: max2027 crashes when using maxscript to display a WPF window

maxencoding — Tue, 19 May 2026 01:26:37 GMT

As mentioned above, simply open 3ds Max 2027 and execute the code `(dotnetObject "System.Windows.Window").Show()` in the script editor. 3ds Max will freeze completely, with no response or output. This is the simplest method I can verify. In my personal WPF project, the UI displays correctly if only `show` is called, but if `set` or `get` is used to interact with the UI, the same problem occurs: 3ds Max freezes and displays no output.

Re: max2027 crashes when using maxscript to display a WPF window

spacefrog_ — Tue, 19 May 2026 03:55:56 GMT

This is what i get:

Re: max2027 crashes when using maxscript to display a WPF window

denisT.MaxDoctor — Tue, 19 May 2026 04:19:55 GMT

This error message is much better than nothing.

Re: max2027 crashes when using maxscript to display a WPF window

denisT.MaxDoctor — Tue, 19 May 2026 16:03:08 GMT

I don't have version 2027, and I don't need to install it yet...

So I recommend trying something like this first:

w = dotnetObject "System.Windows.Window" w.Title = "WPF Test" w.Width = 300 w.Height = 200 hlp = dotnetObject "System.Windows.Interop.WindowInteropHelper" w hlp.Owner = windows.getMAXHWND() w.Show()

We need to figure out where the problem is.

Re: max2027 crashes when using maxscript to display a WPF window

MartinBeh — Tue, 19 May 2026 16:07:42 GMT

This causes 3ds Max to freeze up for 20 seconds and then fast-exit to desktop, no error message.

This is what the Listener shows while doing so:

Re: max2027 crashes when using maxscript to display a WPF window

denisT.MaxDoctor — Tue, 19 May 2026 16:16:31 GMT

how is about ShowDialog() instead?

there is another way to try:

w = dotnetObject "System.Windows.Window" w.Title = "WPF Test" w.Width = 300 w.Height = 200 m = (w.GetType()).GetMethod "Show" m.Invoke w #()

In theory, all should work the same... but it's definitely a MAX's bug, and there might stay some ways that aren't broken.

Re: max2027 crashes when using maxscript to display a WPF window

MartinBeh — Tue, 19 May 2026 16:56:57 GMT

Again, the UI freezes up, fast-exit to desktop.

Here is the Listener output:

Re: max2027 crashes when using maxscript to display a WPF window

denisT.MaxDoctor — Tue, 19 May 2026 16:59:30 GMT

What would I recommend if I urgently needed this in Max 2027 and couldn’t wait for Autodesk to fix the bug?

I would do the following: first, check whether Windows Forms still work. If they do, then I would wrap the WPF window inside a Windows Forms window and launch it through the Form.