flowable/flowable-engine · error · FlowableIllegalArgumentException

Invalid query usage: cannot set both taskAssigneeIds and…

Error message

Invalid query usage: cannot set both taskAssigneeIds and taskAssigneeLikeIgnoreCase

What it means

taskAssigneeIds cannot be combined with taskAssigneeLikeIgnoreCase(String) on the same query. Like the other assignee filters, the case-insensitive LIKE variant is mutually exclusive with explicit assignee-ID matching, and Flowable throws this error to prevent contradictory criteria.

Solutions

Remove the taskAssigneeLikeIgnoreCase(...) call when using taskAssigneeIds.
Centralize assignee filtering in one place so only a single style is applied.
Normalize assignee IDs to one case and use taskAssigneeIds, dropping the ignore-case filter.

Example fix

// before
taskQuery.taskAssigneeLikeIgnoreCase("team-%");
taskQuery.taskAssigneeIds(ids);

// after
if (ids != null && !ids.isEmpty()) {
    taskQuery.taskAssigneeIds(ids);
} else {
    taskQuery.taskAssigneeLikeIgnoreCase("team-%");
}

Defensive patterns

Strategy: validation

Validate before calling

if (assigneeIds != null && !assigneeIds.isEmpty() && assigneeLikeIgnoreCase != null) { throw new IllegalStateException("choose assigneeIds or assigneeLikeIgnoreCase, not both"); }

Type guard

boolean conflict = assigneeLikeIgnoreCase != null && assigneeIds != null && !assigneeIds.isEmpty();

Try / catch

try {
    applyAssigneeFilters(taskQuery, assigneeLikeIgnoreCase, assigneeIds);
} catch (FlowableIllegalArgumentException e) {
    if (!e.getMessage().contains("cannot set both taskAssigneeIds and taskAssigneeLikeIgnoreCase")) throw e;
    logger.error("Conflicting case-insensitive assignee filters", e);
}

Prevention

Normalize assignee IDs once (e.g. lowercase) and use taskAssigneeIds instead of ignore-case LIKE.
Keep a single assignee-filter code path with an explicit mode parameter.
Test queries assembled from multiple optional filter sources.

When it happens

Trigger: Calling taskQuery.taskAssigneeLikeIgnoreCase("team-%").taskAssigneeIds(ids) (either order) on the same TaskQuery instance.

Common situations: A case-insensitive search UI adding an ignore-case filter while another component sets assignee IDs; dynamic query assembly applying every set criterion without checking for conflicts.

Related errors

AI-assisted analysis of flowable/flowable-engine@d6d39ce1c6 (2026-09-11). Data as JSON: /api/errors/d609a8cfaaaa4299. Report an issue: GitHub.

Appendix: source

Thrown at modules/flowable-task-service/src/main/java/org/flowable/task/service/impl/TaskQueryImpl.java:487

            throw new FlowableIllegalArgumentException("Task assignee list is null");
        }
        if (assigneeIds.isEmpty()) {
            throw new FlowableIllegalArgumentException("Task assignee list is empty");
        }
        for (String assignee : assigneeIds) {
            if (assignee == null) {
                throw new FlowableIllegalArgumentException("None of the given task assignees can be null");
            }
        }

        if (assignee != null) {
            throw new FlowableIllegalArgumentException("Invalid query usage: cannot set both taskAssigneeIds and taskAssignee");
        }
        if (assigneeLike != null) {
            throw new FlowableIllegalArgumentException("Invalid query usage: cannot set both taskAssigneeIds and taskAssigneeLike");
        }
        if (assigneeLikeIgnoreCase != null) {
            throw new FlowableIllegalArgumentException("Invalid query usage: cannot set both taskAssigneeIds and taskAssigneeLikeIgnoreCase");
        }

        if (orActive) {
            currentOrQueryObject.assigneeIds = assigneeIds;
        } else {
            this.assigneeIds = assigneeIds;
        }
        return this;
    }

    @Override
    public TaskQueryImpl taskOwner(String owner) {
        if (owner == null) {
            throw new FlowableIllegalArgumentException("Owner is null");
        }
        if (orActive) {
            currentOrQueryObject.owner = owner;
        } else {

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