When Trying to create SmartObjects or Appify a list in SharePoint, you receive the following error:
"Authentication With Server Failed : Security Label not found : (Security label name)"
Navigate to K2 Management and open the Authentication > Claims > Claims node. Check which Security Labels are configured for which issuer.
You want to make sure the SharePoint Security Token Service is pointing to a Security Label that exists, the K2 Security Label in K2 Five or AAD in K2 Cloud.
See the screenshot below.
Make sure that whichever Security Label is using the SharePoint Security Token Service, exists.