flowable/flowable-engine · error · FlowableIllegalArgumentException

caseInstanceId is null

Error message

caseInstanceId is null

What it means

RemoveVariablesCmd removes multiple variables from a CMMN case instance and first validates its inputs. A null caseInstanceId cannot identify a target case, so it throws FlowableIllegalArgumentException immediately.

Solutions

1. Guard the id for null before calling
2. Obtain the id from a freshly created case instance rather than a nullable field
3. Fail fast in your API layer with a 400 when the id parameter is missing

Example fix

// before
cmmnRuntimeService.removeVariables(caseInstanceId, names);
// after
Objects.requireNonNull(caseInstanceId, "caseInstanceId must not be null");
cmmnRuntimeService.removeVariables(caseInstanceId, names);

if (caseInstanceId == null) throw new IllegalArgumentException("caseInstanceId is required");

try { cmmnRuntimeService.removeVariables(id, names); } catch (FlowableIllegalArgumentException e) { log.error("Invalid input: {}", e.getMessage()); }

When it happens

Trigger: Invoking removeVariables(null, names) via the RuntimeService API, e.g. when an optional path/id parameter was not supplied and forwarded as null.

Common situations: REST endpoints with missing id path param; lookup methods returning null that is passed on; test setups forgetting to set the id field.

Related errors

• caseInstanceId is null
• caseInstanceId is null
• caseInstanceId is null
• caseInstanceId is null
• caseInstanceId is null

AI-assisted analysis of flowable/flowable-engine@d6d39ce1c6 (2026-09-11). Data as JSON: /api/errors/a18370f1733f4461. Report an issue: GitHub.

Appendix: source

Thrown at modules/flowable-cmmn-engine/src/main/java/org/flowable/cmmn/engine/impl/cmd/RemoveVariablesCmd.java:40

import org.flowable.common.engine.impl.interceptor.CommandContext;

/**
 * @author Tijs Rademakers
 */
public class RemoveVariablesCmd implements Command<Void> {
    
    protected String caseInstanceId;
    protected Collection<String> variableNames;
    
    public RemoveVariablesCmd(String caseInstanceId, Collection<String> variableNames) {
        this.caseInstanceId = caseInstanceId;
        this.variableNames = variableNames;
    }
    
    @Override
    public Void execute(CommandContext commandContext) {
        if (caseInstanceId == null) {
            throw new FlowableIllegalArgumentException("caseInstanceId is null");
        }
        if (variableNames == null) {
            throw new FlowableIllegalArgumentException("variableNames is null");
        }
     
        CaseInstanceEntity caseInstanceEntity = CommandContextUtil.getCaseInstanceEntityManager(commandContext).findById(caseInstanceId);
        if (caseInstanceEntity == null) {
            throw new FlowableObjectNotFoundException("No case instance found for id " + caseInstanceId, CaseInstanceEntity.class);
        }
        caseInstanceEntity.removeVariables(variableNames);
        
        return null;
    }

}

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