Handle edge cases in export

**Problem**
When working with config, 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 any files, tests, or export entry points. Start by locating the config export flow and its current error handling, then identify the edge cases that produce unhelpful messages. Done means export failures report detailed, actionable errors and the relevant behavior is covered by tests.

Written by the indexing model from the issue text.