"no handler found for uri [/magento2_product_1_v1/document/_bulk] and method [POST]"
The release indexes through a /{index}/document/_bulk endpoint, which needs a mapping type the search engine no longer has. setup:install succeeds and the store loads. The error comes when a product is saved, so it can stay hidden until the first catalogue change.
From one of our run logs
no handler found for uri [/magento2_product_1_v1/document/_bulk] and method [POST]Where we hit it
72 runs, last on 5 October 2026. Each row links to the full answer and the setups that work instead.
| Release line | On | Releases that hit it |
|---|---|---|
| Magento 2.4.5 | OpenSearch 2.19.5 | All 15 |
| Magento 2.4.5 | OpenSearch 3 | All 15 |
| Magento 2.4.4 | OpenSearch 2.19.5 | All 14 |
| Magento 2.4.4 | OpenSearch 3 | All 14 |
| Magento 2.4.3 | OpenSearch 2.19.5 | All 4 |
| Magento 2.4.3 | OpenSearch 3 | All 4 |
| Magento 2.4.2 | OpenSearch 2.19.5 | All 3 |
| Magento 2.4.2 | OpenSearch 3 | All 3 |
Other errors we hit, or check a release and service version.