During processing of web.config section '%1', the parameter '%2' was found to have invalid data. The certificate that was ...

During processing of web.config section '%1', the parameter '%2' was found to have invalid data. The certificate that was identified by the thumbprint '%3' could not be found. 
Section: %1 
Parameter: %2 
Thumbprint: %3 

The Federation Service or the Federation Service Proxy will not be able to start until this configuration parameter is corrected. 

This condition occurs when the thumbprint that is specified does not match the thumbprint of any certificate in the Local Computer Personal store. Common causes for this condition include the following: 
(1) The web.config was edited by hand and the thumbprint string contains a typographical error. 
(2) The certificate with the specified thumbprint is from a user store instead of the Local Computer store. 

User Action 
If the web.config contains a typographical error, correct the thumbprint string. To correct the thumbprint string, open the Certificates snap-in. On the Details tab in the certificate property page, select the Thumbprint field. The thumbprint in the web.config should match the string - with the spaces removed - that appears in the property page. 

If a certificate with a matching thumbprint exists in a user store and a .pfx file for the certificate is available, import the .pfx file directly into the Local Computer Personal store. If no .pfx file is available and the key is exportable, you can create a .pfx file by exporting the certificate with private key. If the key is not exportable and no .pfx file is available, request a new certificate and ensure that the request is for a machine certificate instead of a user certificate.