AuraDB issue: Errors when running CREATE VECTOR INDEX

What Happened

An issue was identified following the deployment of version 2026.06 on 2026-06-30 at 08:00 UTC, where running CREATE VECTOR INDEX on upgraded Aura instances triggered a system exception. This failure in index generation occurred because the underlying store and kernel required additional updates to support the operation

This problem only impacted the creation of new indexes; existing vector indexes are not affected. Any vector index created before 09:00 on 2026-06-30 was unaffected and continued to work normally. 

How the service was affected

Following the rollout of version 2026.06, execution of the CREATE VECTOR INDEX statement failed, impacting applications that depended on adding new vector indexes. Affected clients received the error: Creating a vector index with provided settings is not supported in V2026_02. The required version for operation is V2026_06. Please upgrade DBMS. Existing indexes (created prior to this incident) and other queries remained entirely unaffected and fully functional.

What are we doing now

Neo4j teams identified the root cause as a bug in the Cypher planner and resolved the issue with a code fix. This fix has been deployed to all affected Aura instances, fully resolving the error

To prevent future occurrences, we are enhancing our monitoring and alerting systems to detect similar issues earlier, particularly within staging environments, before rollouts occur. Simultaneously, we are refining our deployment processes to minimize customer impact and recovery times

Additionally, we are investigating options to implement automated, post-upgrade validation tests specifically for critical operations such as vector index creation