It is a known bug in v1.1.4. There is a github issue for it: EvalSumRowsKeyGen()/EvalSumColsKeyGen() incorrect behavior · Issue #773 · openfheorg/openfhe-development · GitHub We will fix it in v1.2.0 (to be released within 2-3 weeks). It works correctly in v1.1.2. Also, there are multiple topics on this bug in the Discourse forum, e.g., Error in EvalSumRows "Input evaluation key map is empty" - #3 by ManhBui