flowable/flowable-engine · error · FlowableIllegalArgumentException

caseInstanceIds are null

Error message

caseInstanceIds are null

What it means

BulkDeleteCaseInstancesCmd.execute throws FlowableIllegalArgumentException when the caseInstanceIds collection is null. Bulk commands delegate to DeleteCaseInstanceCmd per id, so a null collection cannot be iterated; the command fails fast with a clear message.

Source

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

import org.flowable.common.engine.api.FlowableIllegalArgumentException;
import org.flowable.common.engine.impl.interceptor.Command;
import org.flowable.common.engine.impl.interceptor.CommandContext;

/**
 * @author Christopher Welsch
 */
public class BulkDeleteCaseInstancesCmd implements Command<Void> {

    protected Collection<String> caseInstanceIds;

    public BulkDeleteCaseInstancesCmd(Collection<String> caseInstanceIds) {
        this.caseInstanceIds = caseInstanceIds;
    }

    @Override
    public Void execute(CommandContext commandContext) {
        if (caseInstanceIds == null) {
            throw new FlowableIllegalArgumentException("caseInstanceIds are null");
        }
        Set<String> instanceIdSet = new HashSet<>(caseInstanceIds);
        for (String instanceId : instanceIdSet) {
            DeleteCaseInstanceCmd command = new DeleteCaseInstanceCmd(instanceId);
            command.execute(commandContext);
        }
        return null;
    }
}

View on GitHub (pinned to d6d39ce1c6)

Solutions

1. Pass a non-null collection (an empty list is fine) to bulkDeleteCaseInstances
2. Coalesce null to Collections.emptyList() at the call site
3. Guard the call: only invoke bulk delete when the id list was actually populated

Example fix

// before
cmmnRuntimeService.bulkDeleteCaseInstances(ids); // ids may be null
// after
cmmnRuntimeService.bulkDeleteCaseInstances(ids == null ? Collections.emptyList() : ids);

if (caseInstanceIds == null) caseInstanceIds = Collections.emptyList();

boolean isNonNullCollection(Collection<?> c) { return c != null; }

try {
    cmmnRuntimeService.bulkDeleteCaseInstances(ids);
} catch (FlowableIllegalArgumentException e) {
    log.error("Bulk delete rejected: {}", e.getMessage());
}

When it happens

Trigger: Calling cmmnRuntimeService.bulkDeleteCaseInstances(null) or constructing BulkDeleteCaseInstancesCmd with a null collection — e.g. an upstream query that returned null instead of an empty list.

Common situations: A repository/service method returning null when no ids matched; deserialization of an empty request body into a null field; unguarded variable passing.

Related errors

• historic case instanceIds are null
• tasks are null
• caseInstanceIds are null
• caseInstanceId is null
• variable name is null

AI-assisted analysis of flowable/flowable-engine@d6d39ce1c6 (2026-09-11). Data as JSON: /api/errors/105a360c3faa405c. Report an issue: GitHub.