KB-2434 Kafka event consumer fails to start with "Not authorized to read from the selected topic" error (APNX-1-4598-047) after upgrading to Appian 26.9

Symptoms

1. Kafka Event Consumer fails to start with error: Not authorized to read from the selected topic (APNX-1-4598-047).
2. The Kafka Connected System successfully tests connection.
3. Test Event Consumption successfully reads messages from the topic.
4. Issue occurs only after upgrading from Appian 26.6 to 26.9 with identical configuration.
5. Same configuration works on 26.6 environment.

Relevant log output:

YYYY-MM-DD HH:MM:SS,mmm [pc-pool-XXX-thread-X] ERROR com.appiancorp.message.integrations.kafka.exceptions.DefaultConsumerExceptionHandler - Shutting down consumer for integration XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX due to exception: APNX-1-4598-047 Not authorized to read from the selected topic.

YYYY-MM-DD HH:MM:SS,mmm [pc-pool-XXX-thread-X] ERROR com.appiancorp.message.integrations.kafka.processor.IntegrationMessageProcessor - Processing IntegrationRequest [IntegrationRequest[integrationUuid=XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX, operation=ACTIVATE, consumerCount=X, processorCount=X]] failed

com.appiancorp.suiteapi.common.exceptions.AppianException: Not authorized to read from the selected topic. (APNX-1-4598-047)

Cause

This issue has been hotfixed via AP-77045 in Appian 26.9.

Since Appian 26.9, the product checks the service account's topic permissions by querying the broker for allowed operations. Some Kafka brokers leave READ out of the permission response even though reading works, which causes Start to report "Not authorized to read from the selected topic" while Test Event Consumption succeeds.

Action

Apply the latest hotfix to your Appian installation (26.9.170.0 or newer).

The fix (AP-77045) verifies access through the consumer's actual reads instead of depending on how the broker reports permissions.

Affected Versions

This article applies to Appian 26.9.

Last Reviewed: November 2026