Duplicate Backend Layout Identifiers in Page TSconfig – Missing Uniqueness Check
22.2K reputation · 09 Jul 2026, 13:12 UTC
Duplicate Backend Layout Identifiers in Page TSconfig
The goal is to guarantee that each backend layout defined in Page TSconfig uses a unique identifier so that the backend layout dropdown reflects all available layouts and the rendered column structure matches the intended definition.
In TYPO3 10 LTS and 11 LTS the Page TSconfig parser processes entries under mod.web_layout.BackendLayouts. without checking whether already exists, allowing duplicate keys to be registered silently. When duplicates occur, the dropdown shows a single entry but the internal layout object used for rendering is taken from the last definition processed, which can cause unexpected column assignments and is hard to detect in multi‑extension projects.
Given this silent overwriting behavior, what practical steps can integrators take to identify duplicate identifiers during development or deployment? Are there configuration hooks, scheduler tasks, or extension points that can enforce uniqueness at runtime? Does a future TYPO3 release plan to add validation similar to the Site Configuration system?
