Non-trusted certificate

The FTPS and SFTP features of Microsoft Expression Web use the Secure Sockets Layer (SSL) protocol, which uses a combination of public-key and symmetric-key encryption to secure the file transfers between your computer and the server.

SSL encryption requires that a digital security certificate be installed on the web server A certificate is a digital document that verifies the identity of a person or indicates the security of a website. A certificate is issued by a trusted company known as a Certification Authority (CA).

When Expression Web attempts to connect to a secure server, the certificate is automatically checked. If a problem with the certificate occurs, a "non-trusted certificate" error is displayed to let you know that the connection to the server may not be secure.

Certificate errors

Certificate errors occur when there is a problem with a certificate or the way the server uses the certificate. If a problem with the certificate occurs, one of the following error messages will be displayed:

Error Meaning

The certificate for this server has expired or is not yet valid.

This error is displayed if the valid date range of the certificate does not match the current date. This error occurs when the current date is either before or after the time period during which the certificate is valid. Websites must renew their certificates with a certification authority to stay current. Outdated certificates can be a security risk. After a certificate expires, the Certification Authority that issued the certificate is no longer responsible for ensuring that the certificate is not misused.

The certificate for this server has been revoked.

The CA that issued the certificate for this server has since revoked it. This error message often indicates that the security certificate was obtained or used fraudulently by the website. The encryption key that is specified in the certificate might have been compromised or the user listed in a certificate does not have authority to use it (for example, the company was sold).

The certificate for this server was issued by an unknown authority.

The certificate was not issued by a known CA. This error occurs when the certificate has been issued by a certification authority that is not recognized. It is unlikely that this error will occur on a legitimate business or banking site. Phishing sites often attempt to use fake certificates that will trigger this error.

The certificate for this server was issued by an untrusted authority.

The certificate was not issued by a trusted CA. This error occurs when the certificate has been issued by a certification authority that is not recognized. It is unlikely that this error will occur on a legitimate business or banking site. Phishing sites often attempt to use fake certificates that will trigger this error.

The certificate for this server does not have a valid certificate chain to a trusted root authority.

The certificate was issued by an intermediate CA that does not have a certificate chain to a trusted root authority. This error occurs when the certificate has been issued by a certification authority that is not recognized. It is unlikely that this error will occur on a legitimate business or banking site. Phishing sites often attempt to use fake certificates that will trigger this error.

The certificate for this server is malformed.

There may have been a problem with the transmission of the certificate to your computer or it may not be a valid certificate. The error can potentially occur because a certificate has been corrupted, tampered with, is written in an unknown format, or is unreadable. You should not trust the identity of the site if the certificate has this error.

The hostname for this server does not match the hostname in the certificate.

This error indicates that a website is using a digital certificate which was issued to a different web address. This error can also occur if a company owns several websites and uses a certificate that was issued for one web address for another site (for example, for a different department or division). This error should only be ignored if you are confident that the site really is related to the website on the certificate.

An unknown error occurred while validating the certificate for this server.

Certificate validation failed for an unknown reason. The error can potentially occur because a certificate has been corrupted, tampered with, is written in an unknown format, or is unreadable.

See also

Tasks

Connect to a server with FTP

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