## The problem
Issue langgenius/dify#29750 (closed, 43 comments): ### Self Checks - [x] I have read the [Contributing Guide](https://github.com/langgenius/dify/blob/main/CONTRIBUTING.md) and [Language Policy](https://github.com/langgenius/dify/issues/1542). - [x] This is only for bug report, if you would like to ask a question, please head to [Discussions](https://github.com/langgenius/dify/discussions/categories/general). - [x] I have searched for existing issues [search for existing issues](https://github.com/langgenius/dify/issues), including closed ones. - [x] I confirm that I am using English to submit this report, otherwise it will be closed. - [x] 【中文
## The verified fix
Contributor fatelei dug to the root cause: retrieval fails when doc_ids contains 101 UUIDs but works with 100 - the where-condition exceeds the limit with >100 files in a filtered workflow retrieval. Fix inside the api container: uv add 'protobuf[below 5.0.0]=4.21.0' types-protobuf<5.0.0, then restart the api docker. Reporter confirmed: 'I am glad that this issue has been resolved and the test has passed.'