Symptoms

When attempting to start a workflow manually from a list in Sharepoint 2010, the Manual Start page does not load it continuously spins. The following error is logged on the K2 Server:

8060 ProcessPacker Errro, Authentication With Server Failed: ID4175: The issuer of the security token was not recognized by the IssuerNameRegistry. To accept security tokens from this issuer, configure the IssuerNameRegistry to return a valid name for this issuer.
 

Diagnoses

There was a recent Sharepoint 2010 Farm migration and as such the thumprint for the Sharepoint Token Service will likely have changed.
 

Resolution

To resolve this issue, the Sharepoint Powershell below to retrieve the new Farm's Thumbprint:

(Get-SPServiceApplication -Name SecurityTokenServiceApplication).SigningCertificateThumbprint

This entry was updated in the Identity]. ClaimIssuer] table for the Sharepoint Token Service as this is a new Sharepoint Farm.

Afterward, a mapping was updated in the wIdentity]. ClaimTypeMapping] table to map this Sharepoint Token Service to a K2 Label. A K2 Blackpearl service restart was perfomed to resolve the issue.