The page's language code is not valid
html-lang-validOur plugin repairs this
The page declares a language, but the code used is not one software recognises.
Who this affects
Screen reader users, who get the wrong pronunciation rules applied.
Fix it in WordPress
Change the site language under Settings → General, or check whether a multilingual plugin is writing a malformed code.
What the fix is, technically
Use a valid BCP 47 code such as en, en-US, bn-BD or tr-TR.
Or let the plugin do it
This is one of the failures AccessVane can repair for you. It changes the pages your server actually sends, not a script layered on top, and switching the repair off puts everything back exactly as your theme had it.
About the WordPress pluginDoes your site have this problem?
Scan any page free and find out in about fifteen seconds. No signup, and nothing about your site is stored.
Check my page