Symptoms
Claim based authentication
Diagnoses
The errors that is displayed upon SharePoint when configuring SharePoint features for site collections is the following:
This page contains one or more errors. Fix the following before continuing:
•Unable to connect to Host Server.
•Authentication With Server Failed : Value cannot be null. Parameter name: token
Resolution
The following document below gives some good insight on how to set up Claims correctly in conjunction with SharePoint.
https://help.k2.com/onlinehelp/k2blackpearl/icg/4.6.6/webframe.html_claims_authentication_configuration.html
This details out the correct way to configure Claims Based Authentication.
Double check the Database to check the 'Claim Issuer' table to see if the correct thumbprints had been set.
Furthermore check to see if the correct settings had been applied to the HostServer.config file in regards to the thumbprints.
Before applying anything to the config file stop the service. Apply the correct configurations where necessary. Restart the service. From the command prompt run a IIS Reset.
No errors should be displayed in SharePoint no longer.