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FAQ • Support

The .htaccess Edit That Broke a Page It Never Touched

Field Note #142
🔬 Generalized 🟡 Intermediate ⏱ 30 Minutes ✓ Observation from Experience
You add one small rule to .htaccess — nothing dramatic, just a header for a specific file. Something breaks immediately, so you undo it right away, carefully, deleting exactly what you added. And yet: a completely unrelated part of the site is now returning “Page Not Found” on content that loaded fine an hour ago.
You didn’t touch that content. You didn’t touch its URLs. So why does it 404 now?

What’s actually happening
.htaccess isn’t just holding your one new rule — it’s also where WordPress keeps its own rewrite rules, the ones responsible for turning a clean URL like /your-page/ into something the server actually knows how to serve. That block of rules is clearly marked (bookended by comments like # BEGIN WordPress and # END WordPress), and it’s meant to be left alone.
When you’re editing that same file for an unrelated reason — even just adding and then removing a rule — it’s easy for that surgical edit to nick the edge of WordPress’s own block without meaning to. Nothing dramatic has to go wrong. A line ending up slightly off, or the block getting saved in a subtly different state than WordPress expects, is enough. WordPress doesn’t necessarily throw an error when this happens — it just quietly stops rewriting URLs correctly for anything that depends on custom rewrite rules, which is exactly what a non-default post type’s URL structure needs.

How to tell the difference
The specific tell: pages using WordPress’s default structure (the homepage, standard posts and pages) keep working fine, while anything using a custom URL pattern — a custom post type, a specific permalink structure — starts 404ing. If it’s really “some pages broke, others didn’t,” and the broken ones all share a custom URL structure, that pattern points straight at the rewrite rules rather than the content itself.

The fix
In wp-admin, go to Settings → Permalinks.
Don’t change anything. Just click Save Changes as-is.
This forces WordPress to regenerate its rewrite-rules block in .htaccess from scratch, cleanly — which resolves the vast majority of cases without needing to touch the file by hand at all.
Reload the previously-broken page and confirm it’s back.

How to avoid it next time
Any time you need to edit .htaccess for something unrelated to permalinks, treat it as a two-step job, not one: make your edit, then resave Permalinks afterward as a matter of course — even if nothing looks broken. It costs nothing, it’s the same fix either way, and it means you find out immediately rather than being confused later about why something that has nothing to do with your edit suddenly stopped working.

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