Question/Problem
The event log outputs “HttpListener failed to start on http://127.0.0.1:xxxx: System.Net.HttpListenerException (5): Access is denied.” I would like to know the cause of this issue.
Resolution
Cause
This is output when the JavaScript SDK for Robot (UiPath.RobotJS) is not running.
Reference:
About the Robot JavaScript SDK
Excerpt:
When using the JavaScript SDK for Robot (UiPathRobot.js), you can directly embed local Attended robots into existing applications.
Solution
Please verify whether your robot is an Attended or Unattended robot. If you are using an Unattended robot, the JavaScript SDK for Robot (UiPathRobot.js) functionality is unnecessary.
By disabling this functionality, the error will no longer be recorded, so please disable it using the following method:
■ Steps to disable
Control Panel > Programs and Features > UiPath Studio > Change > Next > Modify > Change “JavaScript Add-on for Robot” to “Do not install”.
Additionally, a solution for users of Attended robots is to keep the same process running to resolve the error. Navigate to Control Panel > System and Security > Administrative Tools > Services, and open the properties of “UiPath RobotJS Service” and select “Automatic” or “Automatic (Delayed Start)”.
Error
UiPath.RobotJS.UserHost 22.10.11.0
HttpListener failed to start on http://127.0.0.1:xxxxx: System.Net.HttpListenerException (5): Access is denied.
at System.Net.HttpListener.AddPrefixCore(String registeredPrefix)
at System.Net.HttpListener.AddPrefix(String uriPrefix)
at UiPath.RobotJS.Shared.Implementation.HttpListenerBase.AddListenerPrefixes(String uri)
at UiPath.RobotJS.Shared.Implementation.HttpListenerBase.Start(Int32 portNumber), HResult -2147467259