If a WordPress block's Wide width or Full width option says Not available, inspect its parent container before adding CSS. The block can support an alignment that its surrounding layout does not offer.
Recent Gutenberg changes make some unavailable options visible instead of silently hiding them. That message explains availability, not the full cause. It is not by itself evidence that the editor broke or your saved content was deleted.
Find the parent that controls the block
Use List View to locate the selected block and its immediate ancestors. A Group inside another Group is not the same layout context as the top-level content. Record whether the parent is a normal Group, Row, Grid or the template's Content block.
Test a copy of the affected page on staging. Keep the original template and block markup available for comparison. Do not edit a shared template just to make one photograph wider until you know which other pages use it.
In the updated alignment behavior, a flow parent can leave Wide and Full unavailable. Group and Columns may now show a menu explaining that restriction where the alignment control previously disappeared. A Row or Grid arranges its own children and is a different case, so do not expect the same alignment menu there.
Locate: Inspect the immediate parent. Compare: Flow versus constrained layout. Preview: Measure actual public width. Retest: Check siblings and mobile overflow. Proposed verification, not a customer test result.
Use a two-container comparison
Build a small test page containing two parent Groups and the same Image inside each. Use a synthetic or licensed test image, not a private customer upload.
- On the first parent, turn off Inner blocks use content width if that setting is available in your build.
- Select its child Image and record the alignment choices.
- On the second parent, enable the content-width layout and inspect the same choices.
- Set a wide alignment only where the menu supports it, then save and preview the page.
- Compare the editor with the logged-out public output at the same viewport width.
The upstream change describes the first case as unavailable and the content-width case as offering the supported alignments again. Your theme and block still need to support the requested layout. Record exact WordPress and Gutenberg versions because older interfaces may hide the choices instead of displaying an explanation.
Choose the scope of the correction
If the parent layout is wrong for the design, change that parent and retest its siblings. If the selected block sits inside a Row or Grid, decide whether it belongs in that layout or should move to a different container. Avoid changing an entire template's layout merely to force a single child across the page.
If the control is enabled but the public block remains narrow, you have a second diagnostic. Inspect the rendered wrapper, saved alignment, parent width and computed CSS. Look for a theme rule limiting width, parent padding, or a custom wrapper added by a plugin.
The theme's contentSize and wideSize establish layout dimensions, but Full width does not necessarily mean edge-to-edge browser pixels through every ancestor. A bounded wrapper or padding can still constrain the visible result. Compare the intended design with actual computed dimensions before declaring a failure.
Do not start with a global negative margin or a 100vw rule. Those can create horizontal overflow, including on pages that were already correct. A narrowly scoped fix belongs on the specific layout responsible for the restriction.
Check interaction as well as appearance
In the updated menu, unavailable choices can remain focusable so their explanation can be reached by keyboard and assistive technology. Focus does not mean the action is enabled. Activating an unavailable option should not change the alignment.
Retest the final page on a narrow viewport, with a long caption and with a second block beside the image. Confirm there is no sideways scroll and that the shared template still works on another page. Reopen the editor to verify the saved setting rather than relying on a preview alone.
Use the block-theme regression checklist for wider template testing. If parent settings and frontend CSS disagree, HandL WP can trace the layout constraint from saved markup to the rendered page.
Sources: alignment availability change and WordPress theme layout settings. Diagrams illustrate layout relationships, not screenshots of a particular WordPress release.
References reviewed October 20, 2026. Diagrams and test fixtures are explanatory, not customer results.