Controls disappear on mose over

• .NET Core Version: 5.0.200-preview.20601.7)
• Windows version: 19042.746
• Does the bug reproduce also in WPF for .NET Framework 4.8?: No
• Is this bug related specifically to tooling in Visual Studio: No

Problem description: Controls on mouse hover disappear spontaneously.

Actual behavior: In example below just run the app and quickly move mouse over buttons and you will see that from time to time buttons will disappear.

Expected behavior: Moving over buttons should only change default background color.

Minimal repro:

1. Create new WPF (.NET) project in Visual Studio 2019
2. use following code as main window content

<StackPanel>
      <Button Content="1" />
      <Button Content="2" />
      <Button Content="3" />
      <Button Content="4" />
</StackPanel>

1. run app
2. move mouse over buttons

[weltkante]

This looks suspiciously like the other rendering issues caused by faulty third party software injecting itself into the .NET Core process because they haven’t been updated to detect .NET Core properly (#707 has the main discussion I believe). You may want to check for programs like Nahimic or try to run the program on other machines.

[weltkante]

@legistek this issue is closed, tags are probably just leftover. The cause of the problems are third party applications like Nahimic which intrude into other processes incorrectly. For Desktop Framework and some .NET Core versions they seem to have a “whitelist” to disable/adjust this intrusion, but apparently it doesn’t work on all versions of .NET Core. Thats what I take from following the conversations in the issues.

When third party vendors break the operating systems rules there’s little more that can be done than pushing back to them for fixing their code, or uninstalling/disabling it.