Hi ehurley
1. The eVar should have classification structure defined. You can check it from analytics > admin > Report Suites > edit settings> conversion> conversion classification
- You've to ensure the eVar you're classifying via API has classifications defined
- Ensure that number of classification headers you specify in API requests matches with the columns you have defined for that eVar.
- Ensure the user importing data has access to that eVar
2. An eVar would be compatible if the classifications in API request match the classification structure defined on UI for that eVar.