Cannot convert null literal to non-nullable reference type.

Unboxing a possibly null value.

Unboxing a possibly null value.

The variable 'ex' is declared but never used

Possible null reference return.

Possible null reference assignment.

Nullability of reference types in value of type 'KeyValuePair<string, string?>' doesn't match target type 'KeyValuePair<string, string>'.

Possible null reference assignment.

Argument of type 'IEnumerable<KeyValuePair<string, string>>' cannot be used for parameter 'initialData' of type 'IEnumerable<KeyValuePair<string, string?>>' in 'IConfigurationBuilder MemoryConfigurationBuilderExtensions.AddInMemoryCollection(IConfigurationBuilder configurationBuilder, IEnumerable<KeyValuePair<string, string?>>? initialData)' due to differences in the nullability of reference types.

Nullability of reference types in type of parameter 'value' of 'void ReadOnlyConfigurationProvider.Set(string key, string value)' doesn't match implicitly implemented member 'void IConfigurationProvider.Set(string key, string? value)' (possibly because of nullability attributes).