Handle edge cases in serialization

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

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

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

Start by locating the store serialization path and the existing error-handling entry points. Reproduce the reported edge cases, then inspect how current errors are constructed. Done means the relevant serialization failures produce detailed, descriptive messages and the affected cases are covered by tests.

Written by the indexing model from the issue text.