Dereference of a possibly null reference.

Possible null reference argument for parameter 'source' in 'IEnumerable<Category> Enumerable.Where<Category>(IEnumerable<Category> source, Func<Category, bool> predicate)'.

Possible null reference argument for parameter 'json' in 'List<Category>? JsonSerializer.Deserialize<List<Category>>(string json, JsonSerializerOptions? options = null)'.

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

Cannot convert null literal to non-nullable reference type.

Cannot convert null literal to non-nullable reference type.

Cannot convert null literal to non-nullable reference type.

Cannot convert null literal to non-nullable reference type.

Cannot convert null literal to non-nullable reference type.