Exception thrown when using DataGrid in Project Reunion 0.8 RC

[sibille]

Describe the bug

We're getting the following exception when navigating to a page with a DataGrid in an app created with Project Reunion 0.8 RC: Could not load type 'Microsoft.System.DispatcherQueueTimer' from assembly 'Microsoft.WinUI, Version=3.0.0.0, Culture=neutral, PublicKeyToken=de31ebe4ad15742b'.

Steps to Reproduce

Steps to reproduce the behavior:

1. Create a new WinUI 3 Desktop App using the Project Reunion 0.8 RC vsix (or use attached SampleApp)
2. Add a DataGrid to the MainWindow.xaml
3. Start the App
4. See error

Could not load type 'Microsoft.System.DispatcherQueueTimer' from assembly 'Microsoft.WinUI, Version=3.0.0.0, Culture=neutral, PublicKeyToken=de31ebe4ad15742b'.

Environment

NuGet Package(s): CommunityToolkit.WinUI.UI.Controls.DataGrid

Package Version(s): 7.0.2

Windows 10 Build Number:
- [ ] Fall Creators Update (16299)
- [ ] April 2018 Update (17134)
- [ ] October 2018 Update (17763)
- [ ] May 2019 Update (18362)
- [x] May 2020 Update (19041)
- [ ] Insider Build (build number: )

App min and target version:
- [ ] Fall Creators Update (16299)
- [ ] April 2018 Update (17134)
- [x] October 2018 Update (17763)
- [ ] May 2019 Update (18362)
- [x] May 2020 Update (19041)
- [ ] Insider Build (xxxxx)

Device form factor:
- [x] Desktop
- [ ] Xbox
- [ ] Surface Hub
- [ ] IoT

Visual Studio
- [ ] 2017 (version: )
- [x] 2019 (version: 16.10.2)
- [ ] 2019 Preview (version: )

DataGridExample.zip

Hello sibille, thank you for opening an issue with us!

I have automatically added a "needs triage" label to help get things started. Our team will analyze and investigate the issue, and escalate it to the relevant team if possible. Other community members may also look into the issue and provide feedback 🙌

[Kyaa-dost]

@sibille have you tried using the latest version of Toolkit? FYI @azchohfi ⬆️

[mrlacey]

I can still reproduce this issue with 7.0.3 and WinUI 0.8.1
repro project at microsoft/microsoft-ui-xaml#5451 (comment)

[michael-hawker]

@azchohfi thoughts on this issue? I'm going to move it to our next milestone as we'll be more focused on WinUI specifically then.