Support backup configuration

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

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

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

No files, tests, or entry points are named. Start by locating the controller error paths and clarify whether the goal is backup configuration support or more descriptive controller errors; done should be defined by agreed behavior and tests covering it.

Written by the indexing model from the issue text.