Application is not supported in a Windows Presentation Foundation (WPF) project

Question

I've just created a new WPF project in the blend, pushed it on git, added mqsql drivers, rest service and nfc sdk and suddenly blend tells me that Application is not supported. The error leads me to App.xaml which is entirely unedited and looks like this:

<Application x:Class="desktop_client.App"
         xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
         xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
         xmlns:local="clr-namespace:desktop_client"
         StartupUri="MainWindow.xaml">
<Application.Resources>

</Application.Resources>

The same error goes for practically any tag such as Style, Setter, ControlTemplate, Canvas, Path. nothing is supported. comparing both the xaml and the c# file to the other project I just finished which works just fine, there is no difference (other than namespace and the path, naturally)

I'm absolutely dumbfounded

dvdhns · Answer 1 · 2018-11-07T19:27:16.920

74

Had same issue in VS. I closed and restarted VS and no longer got the error.

edited Nov 07 '18 at 19:27

answered May 04 '17 at 22:16

dvdhns

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Oftentimes the best solution. – J. Doe Sep 04 '18 at 12:00
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Classic. That fixed the issue for me as well. – Brian Sep 19 '19 at 19:39

score 16 · Accepted Answer · answered Mar 19 '17 at 12:29

16

Try adding the following references:

PresentationCore
PresentationFramework
WindowsBase

With the ReferenceManager in your project. The above references are the references used by wpf.

answered Mar 19 '17 at 12:29

MattFisch

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Thanks. System.Xaml will also be required, to build the project. – Gedeon Sep 15 '17 at 05:25
1

I needed WindowsFormsIntegration too. – dperez May 06 '20 at 14:47

ShloEmi · Answer 3 · 2021-10-12T06:09:04.083

13

So old, still occurs - to save time for others - this is the solution that works in VS-2019, as @"Andreas Forslöw" wrote:

Even easier: Right click the project in Solution explorer, click "Unload project". Then, when unloaded, right click again and click "Reload project". Worked for me! – Andreas Forslöw

edited Oct 12 '21 at 06:09

answered Sep 05 '21 at 10:42

ShloEmi

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In my case VS 2019 restart (top-voted answer from @dvdhns) and even win10 reboot didn't help, but this solution worked fine! – sarh Aug 25 '22 at 10:43

Application is not supported in a Windows Presentation Foundation (WPF) project

3 Answers3

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