If you are using Apollo Client JS the CHANGELOG identifies 2 pontential things from 3.8.4 to 3.12.9. I found these by searching the word “breaking”. We always try to avoid any breaking changes in a non-major version but some may be needed when fixing critical bugs on low use or deprecated surface area.
- 3.10.4 deprecated the QueryReference and how preloadQuery returns
- 3.11.0 changes the error type to GraphQLFormattedError. This should be internal as it was actually a type bug but something to check for.
To validate I would jump to 3.10.4 and run your client tests and integration validation, then do the same to 3.11.0 then finally to 3.12.9