Symptoms

Cannot connect to SharePoint after 4.6.10 upgrade
 

Diagnoses

_1
An unexpected failure was encountered when contacting SharePoint to get information from the group provider rGroupProviderName]: K2 Server does not have the necessary permissions on the SharePoint server or cannot authenticate with the server.
InnerException: The request failed with HTTP status 401: Unauthorized.

_2
24148 The User Manager 127.0.0.1 returned an empty queue.

_3
After upgrading to 4.6.10, Sharepoint V2 "Single Line of Text" NULL filters does not seem to work anymore.
 

Resolution

_1
Somethings to check:
a. Are you able to browse to the URL associated with the Group Provider using the K2 Service Account?
b. Is the K2 service account a Site Collection Administrator for this site collection?
c. Please try an reactivation of the K2 Features to this site collection.

_2
This is usually logged if there is a role that does not resolve to at least one valid user. You can also execute the 'UmUser' > 'Get Role Users' method to check if any role is not returning at least one valid user. This error can usually be safely ignored if you do not see any issues as it may be a role that you are not using. Alternatively, to address the issue you can add a placeholder/valid user to the role that is not resolving to at least one valid user.

_3
A Coldfix was provided to resolve this issue. This coldfix will need to be applied on all Sharepoint App Servers and WFEs, as well as all K2 Server nodes. Certain assemblies will need to be GAC'ed on both the Sharepoint servers and K2 servers. Please copy the unzipped coldfix file onto the relevant servers and check the file's Properties please "Unblock" the file if applicable.

Stopping and starting the "K2 blackpearl server" service will be necessary as well as performing IISresets. The "RemoveK2Label" service key will be a part of the service instance after application of the coldfix. Please open a ticket and request if fix if the situation applies.