EXT:seo, Side Properties and Detail Extension
Compare a canonical override with the target's page status, slug, and site base. In the case of detailed pages, additionally check the actually existing data set.
Open the dataset of the affected page and compare a set canonical override with the site base and the real language URL. In the case of a news or product detail page, you also check whether the extension brings in its own canonical source. A fixed target fluid snippet shall not double the dynamic assignment.
Where to check the setting in TYPO3
In TYPO3 13.4, control the SEO page properties and output of EXT:seo. For detailed pages, you also check the CanonicalGenerator or adjustments to the extension. Do the site’s basic URL and language configuration match the published target?
Example of this specific finding
Illustrative control case: /article/? ref=mail refers via canonical to /alter-article/, the target answers with 404. The preferred address no longer contains the intended article.
follow-up audit in TYPO3
Get a default page and a detailed view of the same site. If the finding occurs only in the detailed view, first examine its output instead of the global site configuration.
Determine the appropriate achievable goal and correct the canonical source. Then retrieve the source page and destination separately.
Derogations and scope
Any achievable goal is not a substitute. If the article no longer exists, first clarify the publishing state instead of just the canonical field.
Reference: TYPO3 13.4 with EXT:seo. For other major versions and own extensions, responsibilities may differ; check the actually installed output.
Classify the general error
Definition, system-independent causes and further correction examples: The preferred target must have the intended content