Can't know for sure, but possibly you've put your identity information in the identityMap field and it doesn't match the namespaces in your AEP instance?
Recommendation is to not use the identityMap field - ever - but instead label a string field as a primary identity in your schema. The field must be a string, exactly one string field must be marked as a primary identity, and when loading data, no record can have a blank/null value for this field.
You can see more information here:
https://www.adobe.io/apis/experienceplatform/home/tutorials/alltutorials.html#!api-specification/mar...