This article was created in response to a support issue logged with K2. The content may include typographical errors and may be revised at any time without notice This article is not considered official documentation for K2 software and is provided “as is” with no warranties.

Issue

After Windows and SQL updates (see below) the user couldn't get K2 connect service to connect with the SQL server.
Windows updates: KB3192137 KB3176936 KB4013418 KB4035631 KB4049065 KB4093137 KB4132216 KB4097664 SQL updates: KB4038634 KB4052574 KB4052987 KB4229789 KB4338363 KB4293805

Symptoms

Confirmed that the authentication setup to connect with the SQL server was fine. This did not seem to affect the K2 service.

The following error types were found in the logs:

Please find the below logs which have been provided by the IT admin related to the error, 10/09/2018 15:18:15,Logon,Unknown,Error: 18456 Severity: 14 State: 8.
10/09/2018 15:13:37,Logon,Unknown,Login failed. The login is from an untrusted domain and cannot be used with Integrated authentication. [CLIENT: 10.96.87.24]
10/09/2018 15:13:37,Logon,Unknown,Error: 18452 Severity: 14 State: 1.
10/09/2018 15:13:37,Logon,Unknown,SSPI handshake failed with error code 0x80090346 state 46 while establishing a connection with integrated security; the connection has been closed. Reason: The Channel Bindings from this client are missing or do not match the established Transport Layer Security (TLS) Channel. The service might be under attack or the data provider or client operating system might need to be upgraded to support Extended Protection. Closing the connection. Client's supplied SSPI channel bindings were incorrect. [CLIENT: 10.96.87.24]
10/09/2018 15:13:37,Logon,Unknown,Error: 17806 Severity: 20 State: 46.
10/09/2018 15:13:09,Logon,Unknown,Login failed. The login is from an untrusted domain and cannot be used with Integrated authentication. [CLIENT: 10.96.87.24]
10/09/2018 15:13:09,Logon,Unknown,Error: 18452 Severity: 14 State: 1. 10/09/2018 15:13:09,Logon,Unknown,SSPI handshake failed with error code 0x80090346 state 46 while establishing a connection with integrated security; the connection has been closed. Reason: The Channel Bindings from this client are missing or do not match the established Transport Layer Security (TLS) Channel. The service might be under attack or the data provider or client operating system might need to be upgraded to support Extended Protection. Closing the connection. Client's supplied SSPI channel bindings were incorrect. [CLIENT: 10.96.87.24]
10/09/2018 15:13:09,Logon,Unknown,Error: 17806 Severity: 20 State: 46. 10/09/2018 15:13:09,Logon,Unknown,Login failed. The login is from an untrusted domain and cannot be used with Integrated authentication. [CLIENT: 10.96.87.24] After getting detailed errors from the SQL Server we found that it has something to do with Channel Bindings: The Channel Bindings from this client are missing or do not matched the established Transport Layer Security (TLS) Channel.

Resolution

We concluded this was an issue with the Microsoft Updates and a custom fix was created.
Please contact support for assistance until a new installer is created, a more permanent fix is in the works for future versions of K2.