'Button' does not contain a definition for 'Accepting' and no accessible extension method 'Accepting' accepting a first argument of type 'Button' could be found (are you missing a using directive or an assembly reference?)

'Button' does not contain a definition for 'Accepting' and no accessible extension method 'Accepting' accepting a first argument of type 'Button' could be found (are you missing a using directive or an assembly reference?)

'Button' does not contain a definition for 'Accepting' and no accessible extension method 'Accepting' accepting a first argument of type 'Button' could be found (are you missing a using directive or an assembly reference?)

'Button' does not contain a definition for 'Accepting' and no accessible extension method 'Accepting' accepting a first argument of type 'Button' could be found (are you missing a using directive or an assembly reference?)

Process completed with exit code 1.

Non-nullable field '_menuBar' must contain a non-null value when exiting constructor. Consider adding the 'required' modifier or declaring the field as nullable.

Non-nullable field '_title' must contain a non-null value when exiting constructor. Consider adding the 'required' modifier or declaring the field as nullable.

Non-nullable property 'Data' must contain a non-null value when exiting constructor. Consider adding the 'required' modifier or declaring the property as nullable.

Non-nullable field '_host' must contain a non-null value when exiting constructor. Consider adding the 'required' modifier or declaring the field as nullable.

Unreachable code detected

XML comment has a param tag for 'statusBar', but there is no parameter by that name

Parameter 'output' is unread.

Public method 'TestApply' on test class 'ThemeTests' should be marked as a Fact. Reduce the visibility of the method, or add a Fact attribute to the method. (https://xunit.net/xunit.analyzers/rules/xUnit1013)

Support for 'async void' unit tests is being removed from xUnit.net v3. To simplify upgrading, convert the test to 'async Task' instead. (https://xunit.net/xunit.analyzers/rules/xUnit1048)