Support \ Common Frequently Asked Questions

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SSL Certificate Authority Certification Authorities

This error normally occurs when the root and intermediate certificates (available from our website) are not installed on the web server hosting the site.
Once these certificates are installed on the web server, this issue should be resolved

Full installation instructions for the most common web servers can be found by following the link below:

This error only occurs when the certificate has expired or is not valid yet.
(This can also occur when the client system is set to the wrong time and date)

The certificate common name must match the site name EXACTLY or this error will occur.
To secure a site "" you will need a common name of
The only exception to this is the wild card certificate which can secure * which secures all sub-domains of the

The easiest way to correct this error is to send a new CSR, with the corrected common name, along with your order number to and we will regenerate the certificate for you.

This error occurs then there are "Https://" and "http://" references to items within a web page. You can resolve this by changing these to the correct reference for the type of page (if this is on a secure page, these will need to be "https://" and on a non secure page, they will need to be referenced as http://).

There are a few things that can cause this error; the most common ones are listed below:

1. There is a firewall / router on your network not allowing traffic on the SSL port.
2. The private key for your certificate does not match or is not associated correctly with the certificate
3. The server itself is not configured to run SSL on the desired port, ie the port to listen on has not been entered
4. There is a DNS error on the network or an incorrect DNS mapping.

This error occurs if :

1. You are using the Trust Logo on a domain that you had not purchased it for.
2. The Trustlogo part of the order has not been issued yet.
3. The Javascript is requesting the wrong details. ie : The Javascript is different if you have a Comodo issued SSL certificate or not.

NOTE: The Trust Logo can only be used on a domain that it is purchased for.

This error can be caused by several incorrect fields within the CSR, or the CSR is missing characters when it was pasted into this window.

Things to check:

1. That the key size is between 512 and 8192 bits.
2. The country code is correct
3. The illegal characters in the CSR example (%&?$) and other such illegal characters
4. There are 5 dashes '-' at the start and finish of the BEGIN and END lines

Figure 1

Figure 2

If you get the error shown in Figure 1, this means that a certificate request has already been processed for this domain, and you will need to contact the account holder. If you are an account holder, contact or for your login details. Please note that this request must come from the administrative email address on your account.

To request a certificate for a CSR that gives this error you will need to log into your account as detailed in Figure 2.

My certificate says it has a nonvalid digital signature, what can cause this?

1. The intermediate Comodo certificate has not been installed; you must use the one that came with the site certificate
2. The wrong intermediate Comodo certificate has been installed; you must the one that came with the site certificate