Could not start executor. Rdp connection failed: Message: An authentication failure aborted the connection RemoteException wrapping System.Exception: Could not start executor. Rdp connection failed: Message: An authentication failure aborted the connection., Last error: 131081
Issue Description:
The Unattended HD setup works through an implementation of FreeRDP (an RDP client). The UiPath RobotSvc will create an RDP session via this library from the machine onto itself (a "loopback" RDP session). In the current version that RDP session is initialized using localhost. The problem is when using localhost and enforcing Kerberos authentication for the RDP protocol, there is no SPN record matching localhost in AD, so the token request is denied.
Error: RemoteException wrapping System.Exception: Could not start executor. RDP connection failed: Message: An authentication failure aborted the connection., Last error: 131081
Resolution:
Upgraded the Robot version to 2022.4.9 and added system environment variable "UIPATH_DNS_MACHINENAME" to true.
- Enable the below local group policy to set "Require use of specific security layer for remote (RDP) connections" to RDP and tried the job execution.
Computer Configuration > Windows Components > Remote Desktop Services > Remote Desktop Session Host > Security - Require use of specific security layer for remote (RDP) connections - Set this policy to Enabled and the Value RDP
- Upgrade the Robot version to 2022.4.9 and added system environment variable "UIPATH_DNS_MACHINENAME" to true. Based on this setting robot will use FQDN to create RDP session. In older version it uses localhost to create RDP session. when using localhost and enforcing Kerberos authentication for the RDP protocol, there is no SPN record matching localhost in AD and hence it fails in authentication.
UiPath documentation of bugs found in the past, are presented here for Kerberos authentication Release Notes 2022.4.4.