000465 : <value> does not match the schema of previous inputs.

Description

If the Schema Type parameter is set as TEST,input feature classes or tables must have the same schema.

Solution

Make sure all the input feature classes or tables have the same attribute schemas. If the schemas are not the same, you can set the Schema Type parameter to NO_TEST, so only those fields and their values within the input that match fields within the target dataset are used. See the Append tool documentation for a more detailed explanation.