flowable/flowable-engine · error · FlowableIllegalArgumentException

groupId is null

Error message

groupId is null

What it means

DeleteGroupCmd.execute() checks that the groupId field is non-null before delegating to the GroupEntityManager. A null groupId would be an invalid delete key, so the command throws FlowableIllegalArgumentException at execution time.

Solutions

1. Pass a non-null groupId to IdentityService.deleteGroup() / DeleteGroupCmd.
2. Verify the group exists (createGroupQuery().groupId(id).singleResult() != null) before deleting.
3. In batch deletes, filter out null ids before issuing delete calls.
4. Catch FlowableIllegalArgumentException and surface a 'group id required' validation message to the caller.

Example fix

// before
identityService.deleteGroup(groupId); // groupId may be null

// after
if (groupId != null) {
    identityService.deleteGroup(groupId);
}

if (groupId == null || groupId.isEmpty()) {
    throw new IllegalArgumentException("groupId must be provided before deleting a group");
}

boolean hasValidGroupId(String groupId) {
    return groupId != null && !groupId.isEmpty();
}

try {
    identityService.deleteGroup(groupId);
} catch (FlowableIllegalArgumentException e) {
    if (e.getMessage().contains("groupId is null")) {
        throw new InvalidRequestException("Group id must not be null");
    }
    throw e;
}

When it happens

Trigger: Executing new DeleteGroupCmd(null) directly, or calling IdentityService.deleteGroup(null) which builds this command with a null group id.

Common situations: Group id lost when copying from a DTO or form submission; deleting in a loop where one iteration's id is null because the group was not found earlier; hardcoded cleanup scripts referencing a group that was never created.

Related errors

• group is null
• groupId is null
• groupId is null
• groupId is null
• id is null

AI-assisted analysis of flowable/flowable-engine@d6d39ce1c6 (2026-09-11). Data as JSON: /api/errors/780a6ce8f9e0ec29. Report an issue: GitHub.

Appendix: source

Thrown at modules/flowable-idm-engine/src/main/java/org/flowable/idm/engine/impl/cmd/DeleteGroupCmd.java:37

import org.flowable.common.engine.impl.interceptor.CommandContext;
import org.flowable.idm.engine.impl.util.CommandContextUtil;

/**
 * @author Tom Baeyens
 */
public class DeleteGroupCmd implements Command<Void>, Serializable {

    private static final long serialVersionUID = 1L;
    String groupId;

    public DeleteGroupCmd(String groupId) {
        this.groupId = groupId;
    }

    @Override
    public Void execute(CommandContext commandContext) {
        if (groupId == null) {
            throw new FlowableIllegalArgumentException("groupId is null");
        }
        CommandContextUtil.getGroupEntityManager(commandContext).delete(groupId);

        return null;
    }

}

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