Support » Plugin: AMP » ICU version unknown for AMP

  • Resolved socialmediaverve


    Hello support!

    When I run my site health check tool in WordPress dashboard I get this notification regarding AMP issue. It says “ICU version is unknown, as the constant INTL_ICU_VERSION is not defined”

    When I checked the detail below this it says “the version of ICU can affect how intl extension runs. This extension is used to derive AMP Cache URLs for international domain names (IDNs)”

    Please, this has got me worried because sometimes I notice that my amp pages are not visible in google search, instead I see my normal pages when I conduct a search in Google.

    I notice that this problem only exists when I install this plugin as I have tested my site with other amp plugins without any problem.

    Kinldy help to fix this.

    Thanks for your time!

    The page I need help with: [log in to see the link]

Viewing 15 replies - 1 through 15 (of 17 total)
  • Plugin Author Pascal Birchler


    Hi @socialmediaverve

    It looks like your server is missing the INTL PHP extension, or the extension installed is too low.

    I recommend reaching out to your hosting provider so they can install version 4.6 or higher of the INTL extension.

    Thank you Pascal for your timely response. I will contact them and get back to you for what they say. I don’t know why such extension could be missing from their server.

    Thank you Pascal. I have checked with my host, they say that extension is only available with their vps or dedicated server. Looking to find a way around it.

    Plugin Author Weston Ruter


    This extension is only really needed it if you have an internationalized domain name (with non-ASCII characters). Otherwise it isn’t used, as in your case. We should be update the Site Health test to reflect this, or omit it entirely if the domain site URL is only ASCII.

    Hi Weston,

    Thank you for your insight. I’ve used my site with other AMP plugins without causing error in the site health check tool. My domain name,, is ASCII as you can see so I don’t know why this error occurs in your plugin. This often causes my AMP pages to pull back from showing in Google search, consequently deranking my pages, and triggers SEO error with yoast SEO plugin, saying my site isn’t visible to search engine.

    I expect new updates to resolve this issue. Thanks for your time and effort.

    Plugin Author Weston Ruter


    The Site Health test included in our plugin is probably unique to ours, as we specifically added this custom test. This is why it is not appearing with other plugins. Nevertheless, this test is internal and has no impact at all on whether your pages are indexed.

    Plugin Author Weston Ruter


    Here’s where ICU is being used:

    I’ve filed an issue to suppress this test when a non-IDN domain is being used:

    You can ignore this test in the mean time.

    But I notice that my page loses rankings by the virtue of that site health test error, Yoast SEO also flags my page as SEO error. Maybe it is a case of false-positive that Yoast SEO also displays error when the ICU version is not found in your plugin, but fixing the error might help with SEO. Though it wasn’t like that until recent update.

    Plugin Author Weston Ruter


    The site health test is internal. It is not exposed in any way externally, so it would not be any signal for SEO. I don’t know about how Yoast relates to this.

    Good, that will surely help to fix the issue.

    Plugin Author Weston Ruter


    Yoast SEO does not dictate what the rank will be. It just tries to detect any issues that would negatively impact SEO ranking. It wouldn’t be telling Googlebot how to rank the site based on any Site Health tests.

    Yes, Yoast does not dictate your rank with Google but it can detect your indexability status using their Ryte tool. And when it starts showing warning or error, definitely something is not working properly. The ICU version not found warning also shows validation error for AMP pages in search console

    Plugin Author Weston Ruter


    Please share a screenshot of this validation error in search console regarding the ICU version.

    I don’t know how to post screenshot here but I have posted a few of my amp pages showing error but the post is being held for moderation due to links in it.

    For repeating sake, the following amp pages contain error as shown before them (error: referenced amp URL is not an amp) (error: Disallowed attribute or attribute value present in HTML tag) (error: Disallowed attribute or attribute value present in HTML tag) (error: Disallowed attribute or attribute value present in HTML tag) (error: Disallowed attribute or attribute value present in HTML tag) (error: Disallowed attribute or attribute value present in HTML tag)
Viewing 15 replies - 1 through 15 (of 17 total)
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