Handle edge cases in serialization

**Problem**
When working with data, 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, serialization format, or failing examples are named. Start by locating the serialization and error-handling entry points, then determine which edge cases and message details are required; done should include descriptive errors and tests covering the identified cases.

Written by the indexing model from the issue text.