The app.config sample on this page shows a root node of <compatibility xmlns="urn:schemas-microsoft-com:compatibility.v1">, but should have a <configuration> root node. I suspect this is a copy and paste typo from the app.manifest sample above it.
Edit: The following page has a correct app.config sample usage: https://docs.microsoft.com/en-us/dotnet/framework/configure-apps/file-schema/winforms/
Document Details
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The app.config sample on this page shows a root node of <compatibility xmlns="urn:schemas-microsoft-com:compatibility.v1">, but should have a <configuration> root node. I suspect this is a copy and paste typo from the app.manifest sample above it.
Edit: The following page has a correct app.config sample usage: https://docs.microsoft.com/en-us/dotnet/framework/configure-apps/file-schema/winforms/
Document Details
⚠ Do not edit this section. It is required for docs.microsoft.com ➟ GitHub issue linking.