Improve error messages in lib

**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 points to config error handling in lib but does not name a file, entry point, or test. Start by locating where configuration errors are created and reproduce the current messages. Done means config failures provide more descriptive messages that improve debugging and maintenance.

Written by the indexing model from the issue text.