Error: Error ValidationException: One or more parameter values were invalid: Type mismatch for key X expected: S actual: M

Answered by Rafal Wilinski
Solution
When trying to put or update an item to DynamoDB, you might have tried to write it with incorrect attribute type for example number instead of string or the other way around.
Even though DynamoDB is schemaless, at the table creation you had an ability to specify some AttributeDefinitions. They need to be preserved for all the items in the table.
Other Common DynamoDB Errors (with Solutions)
- AWS Lambda DynamoDB Stream Error
- DynamoDB Failed To Compute Node presentation
- dynamodb cannot create preexisting table
- failed to begin subsegment named 'amazondynamodbv2': segment cannot be found.
- DynamoDB Internal Server Error
- aws.dynamodb.documentclient is not a constructor
- accessdeniedexception dynamodb
- ValidationException: Invalid KeyConditionExpression: Attribute name is a reserved keyword;
- failed to list tables not authorized dynamodb
- One or more parameter values were invalid: some AttributeDefinitions are not used
- could not lookup table in dynamodb
- dynamodb 1 validation error detected value
- DynamoDB Duplicate Key Error
- aws.dynamodb.converter.unmarshall not working
- Unable to start DynamoDB Local process
Tired of switching accounts and regions? Use Dynobase.
First 7 days are on us. No strings attached.
Product Features
DynamoDB Tools
DynamoDB Info
© 2025 Dynobase