Handle edge cases in export

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

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

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

Start by locating the export and auth error-handling entry points in the repository and review how current errors are reported. Identify the relevant edge cases from the existing behavior, then verify that failures produce detailed, useful messages and that the associated checks pass.

Written by the indexing model from the issue text.