[NotNull] or [CanBeNull] attribute is applied to a type that already has the same annotation from nullable reference types

Locating this inspection

By ID

Can be used to locate inspection in e.g. Qodana configuration files, where you can quickly enable or disable it, or adjust its settings.

RedundantNullnessAttributeWithNullableReferenceTypes

Via Settings dialog

Path to the inspection settings via IntelliJ Platform IDE Settings dialog, when you need to adjust inspection settings directly from your IDE.

Settings or Preferences | Editor | Inspections | C# | Redundancies in Code

Suppressing Inspection

You can suppress this inspection by placing the following comment marker before the code fragment where you no longer want messages from this inspection to appear:

More detailed instructions as well as other ways and options that you have can be found in the product documentation:

• JetBrains Rider 2025.2