{"record":{"id":"3273f4cbcf0d8594","repo":"apache/beam","slug":"unable-to-decode-constant-members-from-payload-for","errorCode":null,"errorMessage":"Unable to decode constant members from payload for ParamWindowedValueCoder: ","messagePattern":"Unable to decode constant members from payload for ParamWindowedValueCoder: ","errorType":"exception","errorClass":"java.lang.RuntimeException","httpStatus":null,"severity":"error","filePath":"sdks/java/core/src/main/java/org/apache/beam/sdk/values/WindowedValues.java","lineNumber":1481,"sourceCode":"    public static WindowedValues.ParamWindowedValueCoder<?> fromComponents(\n        List<Coder<?>> components, byte[] payload) {\n      Coder<? extends BoundedWindow> windowCoder =\n          (Coder<? extends BoundedWindow>) components.get(1);\n      WindowedValues.FullWindowedValueCoder<byte[]> windowedValueCoder =\n          WindowedValues.FullWindowedValueCoder.of(ByteArrayCoder.of(), windowCoder);\n\n      try {\n        ByteArrayInputStream bais = new ByteArrayInputStream(payload);\n        WindowedValue<byte[]> windowedValue = windowedValueCoder.decode(bais);\n        return WindowedValues.ParamWindowedValueCoder.of(\n            components.get(0),\n            windowCoder,\n            windowedValue.getTimestamp(),\n            windowedValue.getWindows(),\n            windowedValue.getPaneInfo(),\n            windowedValue.getValueKind());\n      } catch (IOException e) {\n        throw new RuntimeException(\n            \"Unable to decode constant members from payload for ParamWindowedValueCoder: \", e);\n      }\n    }\n\n    private void writeObject(ObjectOutputStream out) throws IOException {\n      out.defaultWriteObject();\n      out.writeObject(getPayload(this));\n    }\n\n    private void readObject(ObjectInputStream in) throws IOException, ClassNotFoundException {\n      in.defaultReadObject();\n      byte[] payload = (byte[]) in.readObject();\n      ParamWindowedValueCoder<?> paramWindowedValueCoder =\n          fromComponents(Arrays.asList(valueCoder, getWindowCoder()), payload);\n      this.windowedValuePrototype = paramWindowedValueCoder.windowedValuePrototype;\n    }\n  }\n}","sourceCodeStart":1463,"sourceCodeEnd":1499,"githubUrl":"https://github.com/apache/beam/blob/12126d8942aaf848030c478b4c6a28c6af861c66/sdks/java/core/src/main/java/org/apache/beam/sdk/values/WindowedValues.java#L1463-L1499","documentation":"The mirror of error 881: ParamWindowedValueCoder deserializes its constant members from a byte payload in its readObject path; an IOException during decode is wrapped in this RuntimeException. It means the coder payload produced at serialization time cannot be decoded.","triggerScenarios":"Deserializing a ParamWindowedValueCoder from its byte payload when the encoded windowed value cannot be decoded - corrupted payload, coder version mismatch, or window coder unable to decode the encoded windows.","commonSituations":"Beam version differences between serialization and deserialization environments; deserialized coder crossing JVM/worker boundaries with incompatible registered coders; corrupted cached coder payloads.","solutions":["Read the 'Caused by' IOException to identify which field failed to decode","Ensure identical Beam SDK versions on all environments that serialize/deserialize the coder","Re-register custom coders in the deserializing environment","Clear stale serialized caches or job artifacts built with older coder versions"],"exampleFix":"// before: mismatched SDK versions between submission and worker\n// pom.xml: beam-sdks-java-core 2.40.0 (submitter), 2.50.0 (worker)\n// after: pin one version everywhere\n<dependency>\n  <groupId>org.apache.beam</groupId>\n  <artifactId>beam-sdks-java-core</artifactId>\n  <version>2.50.0</version>\n</dependency>","handlingStrategy":"try-catch","validationCode":null,"typeGuard":null,"tryCatchPattern":"try { decodePayload(bytes); } catch (RuntimeException e) { if (e.getCause() instanceof IOException) { /* rebuild/re-serialize coder with matching SDK version */ } throw e; }","preventionTips":["Pin identical Beam SDK versions everywhere coders are serialized","Do not persist serialized coder payloads across upgrades without re-serializing","Register custom coders on every JVM that deserializes them"],"tags":["java","beam","coder","deserialization","ioexception"],"backgroundTag":"json-unmarshal-failed","analyzedSha":"12126d8942aaf848030c478b4c6a28c6af861c66","analyzedAt":"2026-09-13T01:50:10.254Z","contentChangedAt":"2026-09-13T01:50:10.254Z","schemaVersion":2},"datasetVersion":"2026-09-14T16:17:12.679Z"}