Handle edge cases in import

**Problem**
When working with api, the error messages could be more descriptive.

**Suggestion**
Improve error handling and add detailed error messages.

**Context**
This would help with debugging and maintenance.

The issue does not name files, tests, or specific import edge cases. Start by locating the import handling and API error paths in the repository, then reproduce the reported failures and identify the expected detailed messages. Done means the relevant edge cases are handled and the resulting errors provide more useful debugging context.

Written by the indexing model from the issue text.