Why am I getting a XAML Designer Error in every single one of my Design Views?

1
votes

I am getting this error in the XAML Designer View in every single one of my XAML views:

The .NET Core 3.0 runtime for 'x64' platform configuration is missing or damaged. Please download and install .NET Core 3.0 SDK for the 'x64' platform. (Exit code: 80008083)

Visual Studio Designer View Error

I did that and it had no effect. I tried installing a bunch of other .net runtimes and no effect. The project is a .net 5.0 WPF application on VS 2019. When I compile the project it works perfectly fine. I just got back into work over the weekend and now this is happening all of a sudden. I also tried a "repair" on visual studio, no effect. I reinstalled Visual Studio and deleted my solution folder and recloned it. No effect.

I created a brand new WPF Net Core 5 project and the XAML designer view works. The only thing I can think of is that some kind of setting or configuration has been altered from the one other employee at my work and it is pointing the solution to the wrong PC name or something for the Designer View stuff. I am not sure where to start with that.

1
c#wpfxamlexceptiondesign-view
I noticed this is from a GreatMaps.NET control I have. If the corresponding projects for it are compiled I get the XAML error. However if I delete all the .dlls from it by deleting the bin folder it will load the design view with a yellow box for the map control. – David Harmon

1 Answers

1
votes

Figured out the issue. Apparently the root cause of this was this tag missing from my projects xaml file.

    <RuntimeIdentifier>win-x64</RuntimeIdentifier>

Adding this in fixed it. Not sure why but basically what I did was went to a demo app that worked and added in the generic xaml lines I was missing and by process of elimination figured out it was this one. It was working a few days ago, but I also share this repo with another person so maybe somehow it got confused it was supposed to have that setting and explicitly listing it fixed it.

No idea why it popped up with a Net Core 3.0 error seeing as it is not used at all in the project. It was really misleading and led me on a wild goose chase.