This is found in LANDesk Management Suite version 9.6 Service pack 2
"Unable to find the remote control web service on <CORE SERVER>"
"Failed short session connection to gateway (3)"
1. This happens when the certificate bound to HTTPS on the core becomes corrupt, missing, or expired.
2. This error can also happen when using the remote control viewer to remote control devices without a core server to authenticate to.
Solution / Workaround:
On your core, open the IIS manager.
On the left, find the "Default Web Site" entity.
Right click it and choose "Edit Bindings" from the list.
In the new window, edit the 443 binding. Change the certificate to one that looks like: "LANDesk Secure Token Server"
If the certificate is already set to the "LANDesk Secure Token Server". This means that you have a bad certificate:
Open your client connectivity settings and look under "Core information". Note which certificates are being used.
If there are many certificates in here, you may need to verify the core name on the certificate and .0 files by opening them in notepad. Check the .crt and .cer expiration dates by double clicking them.
Navigate to \Program Files\LANDesk\Shared Files\Keys and compare to "Core certificates the client will trust". Move the certificates and .0 files that are not in client connectivity (With the exception of LANDesk_CommandsWS) to a new folder. NOTE: File path may vary
Navigate to \Program Files\LANDesk\ManagementSuite\ldlogon and move the .0 files that are not in client connectivity to a new folder. NOTE: File path may vary
Navigate to \Program Files (x86)\LANDesk\Shared Files\cbaroot\certs and move the .0 files that are not in client connectivity to a new folder. NOTE: File path may vary
Add the LANDesk core server name to "Type the authentication core server name:" in the remote control viewer before attempting to remote control.
Make sure that when you ping the CSA name from the core, it is trying to resolve to the internal IP address of the CSA.