flowable/flowable-engine · error · FlowableIllegalArgumentException

Unknown variable type ${variableType}

Error message

Unknown variable type ${variableType}

What it means

getVariableFromRequestWithoutAccessCheck branches on an internal variableType flag (VARIABLE_CASE or VARIABLE_PLAN_ITEM) to decide which runtimeService call to use; any other value triggers FlowableIllegalArgumentException 'Unknown variable type'. This is an internal dispatch guard, hit when caller code passes an unexpected type constant.

Source

Thrown at modules/flowable-cmmn-rest/src/main/java/org/flowable/cmmn/rest/service/api/runtime/caze/BaseVariableResource.java:115

        if (planItemInstance == null) {
            throw new FlowableObjectNotFoundException("Could not find a plan item instance", CaseInstance.class);
        }

        if (restApiInterceptor != null) {
            restApiInterceptor.accessPlanItemInstanceVariable(planItemInstance, variableName);
        }
        return getVariableFromRequestWithoutAccessCheck(planItemInstance.getId(), variableName, CmmnRestResponseFactory.VARIABLE_PLAN_ITEM, includeBinary);
    }

    protected RestVariable getVariableFromRequestWithoutAccessCheck(String instanceId, String variableName, int variableType, boolean includeBinary) {
        Object value = null;

        if (variableType == CmmnRestResponseFactory.VARIABLE_PLAN_ITEM) {
            value = runtimeService.getLocalVariable(instanceId, variableName);
        } else if (variableType == CmmnRestResponseFactory.VARIABLE_CASE) {
            value = runtimeService.getVariable(instanceId, variableName);
        } else {
            throw new FlowableIllegalArgumentException("Unknown variable type " + variableType);
        }

        if (value == null) {
            if (variableType == CmmnRestResponseFactory.VARIABLE_PLAN_ITEM) {
                throw new FlowableObjectNotFoundException(
                        "Plan item instance '" + instanceId + "' doesn't have a variable with name: '" + variableName + "'.",
                        VariableInstance.class);
            } else {
                throw new FlowableObjectNotFoundException(
                        "Case instance '" + instanceId + "' doesn't have a variable with name: '" + variableName + "'.",
                        VariableInstance.class);
            }
        }

        //we use null for the scope, because the extraction from request does not require the scope
        return constructRestVariable(variableName, value, instanceId, variableType, includeBinary, null);
    }

View on GitHub (pinned to d6d39ce1c6)

Solutions

1. Only pass CmmnRestResponseFactory.VARIABLE_CASE or VARIABLE_PLAN_ITEM
2. If adding a new scope type, extend the if/else branch in getVariableFromRequestWithoutAccessCheck
3. Don't reuse BPMN REST response-factory constants in the CMMN module

Example fix

// before
int type = CmmnRestResponseFactory.VARIABLE_TASK; // BPMN constant, unknown here
// after
int type = CmmnRestResponseFactory.VARIABLE_PLAN_ITEM;

if (variableType !== CmmnRestResponseFactory.VARIABLE_CASE && variableType !== CmmnRestResponseFactory.VARIABLE_PLAN_ITEM) {
  throw new Error('variableType must be VARIABLE_CASE or VARIABLE_PLAN_ITEM');
}

const isCmmnVariableType = (t) => t === CmmnRestResponseFactory.VARIABLE_CASE || t === CmmnRestResponseFactory.VARIABLE_PLAN_ITEM;

catch (e) { if (e instanceof FlowableIllegalArgumentException) { /* fix constant */ } }

When it happens

Trigger: Direct/internal calls to getVariableFromRequestWithoutAccessCheck with a variableType other than CmmnRestResponseFactory.VARIABLE_CASE or VARIABLE_PLAN_ITEM (called by getVariableFromRequest, setSimpleVariable, setBinaryVariable).

Common situations: Custom subclasses or extensions of BaseVariableResource passing a new constant without adding a branch; refactoring that removed/renamed a constant; copy-pasted code from the process (BPMN) REST module using its constants.

Understand the failure class

Background: "This is a bug, please report it": internal invariant violations, unreachable panics, and SNH errors explained — this error's family across 47 libraries.

Related errors

• Variable name in the body should be equal to the name used i
• Plan item instance '${id}' does not have a variable '${varia
• Variable operation is missing for variable: ${name}
• Variable name is required
• Task '

AI-assisted analysis of flowable/flowable-engine@d6d39ce1c6 (2026-09-11). Data as JSON: /api/errors/a576101688741688. Report an issue: GitHub.