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)
- dynamodb could not connect to the endpoint url
- dynamodb cannot read properties of undefined
- dynamodb mapper save not persisting
- aws.dynamodb.converter.unmarshall not working
- failed to list tables not authorized dynamodb
- requested resource not found aws dynamodb
- dynamodb list_append if_not_exists not working
- DynamoDB Scan Not Working
- dynamodb does not accept empty set
- ProvisionedThroughputExceededException DynamoDB
- cognitoidentitycredentials is not authorized to perform dynamodb describetable
- dynamodb: one or more parameter values were invalid: type mismatch for index key
- dynamodb cannot convert undefined or null to object
- could not unmarshal the value dynamodb
- accessdeniedexception dynamodb
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