Improve config performance

**Problem**
When working with core, 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 specific config and error-handling entry points. Start by locating the core configuration and error-handling paths, then clarify which errors need more detail and how the requested performance improvement will be measured before defining completion.

Written by the indexing model from the issue text.