Why a certificate error hurts a business
A certificate proves that the connection is encrypted and that the site belongs to the domain owner. When something is wrong with it, browsers replace your page with a warning, and Yandex Webmaster reports the issue in its diagnostics. Visitors rarely click through that screen.
Think about where your traffic comes from. A shopper arrives from a Meta Ads campaign, an Instagram bio link or an OLX listing, and sees a security warning before the catalogue or the order form. If you take payments through Click or Payme, trust matters even more. Meanwhile the ad budget keeps being spent on clicks that produce no enquiries.
Search engines are also more cautious with pages that have https problems, so it is best to fix the error the same day.
Common causes of an invalid certificate
The list of causes is short, and the same ones appear again and again. Start with these.
- The certificate has expired. Free certificates are issued for short periods and are supposed to renew automatically. When renewal quietly breaks, the site suddenly opens with a warning.
- The certificate was issued for a different name. It may cover example.uz but not www.example.uz or a subdomain.
- The chain is incomplete: the server sends your certificate but not the intermediate certificates from the issuing authority.
- A self-signed certificate left over from testing is still on the live site.
- The certificate is installed on only some of your servers.
- The site sits behind Cloudflare or another proxy, and encryption is configured wrongly on one of the two connections.
How to diagnose the problem
Open the site in several browsers and on a phone, ideally both Android and iPhone. Click the padlock or warning icon in the address bar to see which domain the certificate was issued for, who issued it and when it expires. Check both the www and non-www addresses separately.
Then check the chain. This is the sneaky case: the site opens fine on your laptop because the browser filled in the missing link itself, while a crawler or another device fails. Online SSL checkers show whether the chain is complete, which names the certificate covers and which protocols are enabled. Run the check for every version of your address.
How to fix an SSL certificate error
If the certificate has expired, renew it, but do not stop there. Find out why automatic renewal failed. Usually something changed: the hosting was moved, DNS records were edited, or a control panel update stopped the renewal task from running.
If the certificate does not cover a required name, reissue it with every address you use: the main domain, the www version and any subdomains. A single certificate can cover several names.
If the chain is incomplete, install the full chain file on the server; the certificate authority normally provides it as a separate download. A self-signed certificate on a live site should be replaced with one issued by a trusted authority.
Proxies, CDNs and mixed content
When a site is connected to Cloudflare or a similar service, there are really two connections: visitor to proxy, and proxy to your server. The fault can sit on either one, and sometimes shows up only for some requests. Make sure the encryption mode is set correctly and that the origin server has a valid certificate of its own.
Mixed content is a related but separate problem. The page loads over https, yet some images, scripts or fonts are still requested over http. The certificate itself may be fine, but browsers can block those elements or drop the secure padlock. Search templates and the database for http links and switch them to https or relative paths.
Re-checking and prevention
Once everything is fixed, request a re-check in the Yandex Webmaster diagnostics. The message will not vanish instantly, because the robot has to confirm that the certificate is now valid. Look at Google Search Console too, since it reports https problems as well.
A few habits stop the error from returning:
- turn on automatic renewal and test it after every hosting move;
- set up an alert that warns you well before a certificate expires;
- keep a list of domains and subdomains with their expiry dates;
- after any change of hosting or DNS, check the certificate first;
- never leave self-signed certificates on a production site.
When to bring in a specialist
If your site runs across several subdomains, sits behind a proxy and takes online payments, fixing it by trial and error is risky: it is easy to repair one thing and break another. The markdev team builds websites on a turnkey basis and sets up https, redirects and monitoring so the owner does not have to remember certificate dates.
If Webmaster is already showing the error and the cause is unclear, describe the situation to us. We will look at the site, find where the problem comes from and tell you what to fix first.
FAQ
How quickly should I fix an SSL certificate error?
The same day if possible. Every visitor sees the warning immediately, while ads and search keep sending people to a page they will leave.
My site opens fine for me, but Webmaster reports an error. Why?
Most often the chain is incomplete or another version of the address, such as the one without www, is affected. Your browser may have rebuilt the chain on its own, while a crawler does not.
The site is fixed but the message is still in Webmaster. Is that normal?
Yes. The message does not disappear instantly. Request a re-check in diagnostics and wait for the robot to confirm the fix.
Is mixed content also a certificate error?
No, the certificate can be perfectly valid. But http resources on an https page reduce trust and may be blocked by the browser, so they should be replaced too.
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