Error: dynamodb unable to locate property for key attribute

“Unable to locate property for key attribute” comes from the .NET DynamoDB object persistence model when it cannot map a table key attribute to a model member. It does not mean the item is missing. Compare the model’s mapping with the table’s KeySchema.

using Amazon.DynamoDBv2.DataModel;

[DynamoDBTable("Orders")]
public class Order
{
    [DynamoDBHashKey("pk")]
    public string PartitionKey { get; set; } = "";

    [DynamoDBRangeKey("sk")]
    public string SortKey { get; set; } = "";
}

This example maps CLR property names to table attributes pk and sk. Keep both properties readable and writable, and use types matching the actual key types. Check overridden table names, index mappings, ignored members, and inherited properties when the error names a different attribute.

Current .NET SDK code can construct its context with DynamoDBContextBuilder; ensure the model or explicit table metadata supplies the required keys. Adding a random attribute to the stored item will not repair missing client-side mapping metadata.

See key value types and AWS SDK mapping source.