Depending on the cause of your problem, try one of the following resolutions:
- If you do not have a client certificate for the site, and you need one, contact the site administrator for instructions.
- Make sure that the expiration date and time of the certificate has arrived. If your certificate has expired, contact the site administrator for instructions.
Client certificate authentication may be enabled where it is not required. If you intended only to require TLS/SSL communications, then you need only a server certificate. You can disable client certificate authentication by using the resolution in the following Microsoft Knowledge Base article:
Error message when you try to run a Web application that is hosted on a server that is running IIS 7.0: "HTTP Error 403.7 - Forbidden"
To check whether the server running IIS considers the certificate valid, you can follow these steps:
- Export the certificate to a .CER file.
- Copy the .CER file to the server that is running IIS.
- Open the .CER file on the server that is running IIS.
- Look at the Certification Path tab. If all certificates in the chain are displayed without a red "cross," then the certificate chain is trusted by the computer. If the root certification authority has a red cross against it, continue to the next set of steps.
To resolve this issue, install the root certification authority certificate manually. To do this, follow these steps:
- Click Start, click Run, type mmc, and then click OK.
- On the File menu, click Add/Remove Snap-in.
- In the Add or Remove Snap-ins dialog box, select Certificates under Available Snap-ins, and then click Add.
- In the Certificates snap-in, select Computer account, click Finish twice, and then click OK.
- Under Console Root, expand Certificates (Local Computer).
- Expand Trusted Root Certification Authorities, and then right-click Certificates.
- Select All Tasks, and then click Import….
- Click Next, and then navigate to the location where the Root CA certificate file is stored.
- After the certificate has been selected, click Next two times, and then click Finish.
Intermediate CA certificates should be installed in the Intermediate Certification Authorities
store rather than in the Trusted Roots
store. Any certification authority certificate whose Issued by
and Issued to
values are not the same (and therefore the certificate is not at the top of the hierarchy) is known as an "Intermediate CA."