flowable/flowable-engine · error · FlowableObjectNotFoundException

The variable does not have a binary data stream.

Error message

The variable does not have a binary data stream.

What it means

HistoricVariableInstanceDataResource.getVariableData returns the binary/serializable content of a historic variable. For byte-array and serializable types it reads the raw bytes or deserializes the value; if the variable has no binary data stream (e.g. it is a plain string/number or the bytes were deleted), it throws FlowableObjectNotFoundException.

Source

Thrown at modules/flowable-cmmn-rest/src/main/java/org/flowable/cmmn/rest/service/api/history/variable/HistoricVariableInstanceDataResource.java:77

    @ResponseBody
    public byte[] getVariableData(@ApiParam(name = "varInstanceId") @PathVariable("varInstanceId") String varInstanceId, HttpServletResponse response) {
        try {
            byte[] result = null;
            RestVariable variable = getVariableFromRequest(true, varInstanceId);
            if (CmmnRestResponseFactory.BYTE_ARRAY_VARIABLE_TYPE.equals(variable.getType())) {
                result = (byte[]) variable.getValue();
                response.setContentType("application/octet-stream");

            } else if (CmmnRestResponseFactory.SERIALIZABLE_VARIABLE_TYPE.equals(variable.getType())) {
                ByteArrayOutputStream buffer = new ByteArrayOutputStream();
                ObjectOutputStream outputStream = new ObjectOutputStream(buffer);
                outputStream.writeObject(variable.getValue());
                outputStream.close();
                result = buffer.toByteArray();
                response.setContentType("application/x-java-serialized-object");

            } else {
                throw new FlowableObjectNotFoundException("The variable does not have a binary data stream.", null);
            }
            return result;

        } catch (IOException ioe) {
            // Re-throw IOException
            throw new FlowableException("Unexpected exception getting variable data", ioe);
        }
    }
}

View on GitHub (pinned to d6d39ce1c6)

Solutions

1. Check the variable's type before requesting /data; only byte and serializable variables have a binary stream.
2. Handle HTTP 404 from the /data endpoint as 'no binary content' rather than a hard failure.
3. If the blob was deleted by history/purge jobs, re-run the process case or configure retention so variable blobs are kept as long as needed.

Example fix

// before
byte[] data = client.get("/cmmn-history/historic-variable-instances/" + id + "/data");
// after
if (variable.getType().equals("byte") || variable.getType().equals("serializable")) {
    byte[] data = client.get("/cmmn-history/historic-variable-instances/" + id + "/data");
}

const BINARY_TYPES=["byte","serializable"];
if (!BINARY_TYPES.includes(variable.type)) throw new Error(`Variable ${variable.id} has no binary data`);

const hasBinary = v => v.type === 'byte' || v.type === 'serializable';

try { data = fetch(url) } catch (e) { if (e.status === 404) { /* no binary content: treat as empty */ } else { throw e } }

When it happens

Trigger: GET /cmmn-history/historic-variable-instances/{variableId}/data on a variable whose value is a primitive type (string, integer, date) rather than byte[] or Serializable, or whose blob data is no longer present.

Common situations: Scripts assuming every variable has downloadable binary data; variables stored in a database where the act_ge_bytearray row was purged/cleaned; querying serializable variables after DB cleanup jobs removed the data.

Understand the failure class

Background: 'Could not be found', 'does not exist', 'not found in database': the resource-not-found family when an ID, slug, key, or URI lookup comes back empty — this error's family across 20 libraries.

Related errors

• The variable does not have a binary data stream.
• The variable does not have a binary data stream.
• Task '${taskId}' does not have a variable '${variableName}'
• The variable does not have a binary data stream.
• Only string variable values are supported using like, but wa

AI-assisted analysis of flowable/flowable-engine@d6d39ce1c6 (2026-09-11). Data as JSON: /api/errors/7dfb9ff51f0cb0fa. Report an issue: GitHub.