flowable/flowable-engine · error · FlowableIllegalArgumentException

group is null

Error message

group is null

What it means

SaveGroupCmd persists a Group via the GroupEntityManager (insert for new groups, update for existing ones). A null Group object has no id or state to persist, so the command throws FlowableIllegalArgumentException before touching the entity manager.

Solutions

1. Ensure the Group instance is created (identityService.newGroup(id)) before saving
2. Check the preceding lookup/call that produced the null group reference
3. Guard the save call with a null check to skip or create the group as needed

Example fix

// before
identityService.saveGroup(group);
// after
if (group == null) {
    group = identityService.newGroup(groupId);
}
identityService.saveGroup(group);

if (group == null) throw new IllegalArgumentException("group must not be null");

boolean isSavableGroup(Group g) { return g != null && g.getId() != null && !g.getId().trim().isEmpty(); }

try { identityService.saveGroup(group); } catch (FlowableIllegalArgumentException e) { log.error("Attempted to save null group", e); }

When it happens

Trigger: Calling identityService.saveGroup(null) or executing new SaveGroupCmd(config, null); also when a Group variable is expected from an earlier lookup that returned null.

Common situations: Chaining code like saveGroup(findGroup(name)) where the lookup failed; deserializing groups from JSON/config where the field is missing; Spring injection of a group bean that failed.

Related errors

• groupId is null
• groupId is null
• Provided groupId is null
• Provided groupIds is null
• entityClass is null

AI-assisted analysis of flowable/flowable-engine@d6d39ce1c6 (2026-09-11). Data as JSON: /api/errors/96b857c6edd65b42. Report an issue: GitHub.

Appendix: source

Thrown at modules/flowable-idm-engine/src/main/java/org/flowable/idm/engine/impl/cmd/SaveGroupCmd.java:45

 * @author Joram Barrez
 */
public class SaveGroupCmd implements Command<Void>, Serializable {

    private static final long serialVersionUID = 1L;
    
    protected IdmEngineConfiguration idmEngineConfiguration;
    
    protected Group group;

    public SaveGroupCmd(Group group, IdmEngineConfiguration idmEngineConfiguration) {
        this.group = group;
        this.idmEngineConfiguration = idmEngineConfiguration;
    }

    @Override
    public Void execute(CommandContext commandContext) {
        if (group == null) {
            throw new FlowableIllegalArgumentException("group is null");
        }

        if (idmEngineConfiguration.getGroupEntityManager().isNewGroup(group)) {
            if (group instanceof GroupEntity) {
                idmEngineConfiguration.getGroupEntityManager().insert((GroupEntity) group);
            } else {
                CommandContextUtil.getDbSqlSession(commandContext).insert((Entity) group, idmEngineConfiguration.getIdGenerator());
            }
        } else {
            if (group instanceof GroupEntity) {
                idmEngineConfiguration.getGroupEntityManager().update((GroupEntity) group);
            } else {
                CommandContextUtil.getDbSqlSession(commandContext).update((Entity) group);
            }

        }
        return null;
    }

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