Improve error messages in models

**Problem**
When working with components, 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 names no files, tests, or entry points. Start by locating the model error-handling paths, then determine which component failures need more descriptive messages; done means the targeted errors provide useful debugging context and the relevant behavior is covered by tests.

Written by the indexing model from the issue text.