ERROR: 1420, Message - 'Cannot acquire a license.'

Dear all, I need immediate help. Suddenly, all of the attended robots’ processes disappeared from Assistant and it shows “Cannot acquire a license”. In Orchestrator web panel, all of the Attended robots shows disconnected. But the other robots types, including Unattended and Studio are working fine. When I checked Event Viewer of the Orchestrator machine, I found the error below for multiple times:

UiPath.Orchestrator.Core.Exceptions.BusinessConflictException: Error code - 1420, Message - 'Cannot acquire a license.'
   at async Task<RobotDto> UiPath.Orchestrator.Application.Provisioning.DirectoryProvisioner.LoginRobotAsync(string loginName)
   at async Task<RobotDetailsDto> UiPath.Orchestrator.Application.Robot.RobotTerminal.BeginAutoProvisionedSessionAsync(string loginName, MachineContext machineContext)
   at async Task<RobotDetailsDto> UiPath.Orchestrator.Application.Robot.RobotTerminal.BeginAutoProvisionedDirectoryUserSessionAsync(UiUser user, MachineContext machineContext)
   at async Task<RobotDetailsDto> UiPath.Orchestrator.Application.Robot.RobotTerminal.BeginAttendedSessionAsync(RobotIdentifier robotIdentifier)
   at async Task<IActionResult> UiPath.Orchestrator.Web.Api.Api.Controllers.RobotsServiceController.BeginSession(RobotIdentifier identifier)
   at async ValueTask<IActionResult> Microsoft.AspNetCore.Mvc.Infrastructure.ActionMethodExecutor+TaskOfIActionResultExecutor.Execute(IActionResultTypeMapper mapper, ObjectMethodExecutor executor, object controller, object[] arguments)
   at async Task Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.InvokeActionMethodAsync()+Logged(?)
   at async Task Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.InvokeNextActionFilterAsync()+Awaited(?)
   at void Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.Rethrow(ActionExecutedContextSealed context)
   at Task Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.Next(ref State next, ref Scope scope, ref object state, ref bool isCompleted)
   at async Task Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.InvokeInnerFilterAsync()+Awaited(?)
   at async Task Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.InvokeNextExceptionFilterAsync()+Awaited(?)

This is an all-new error to me and I couldn’t find any resource to resolve it. I sincerely request your help. Thanks

@Forum_Staff, need your help, too.


Can you check Orchestrator has the available license?

Also check what error you are trying to connect Assistant to Orchestrator


Yes, Orch has enough licenses left. The error is from Assistant’s side is “connected unlicensed”.


I suggest to check below documentation for connecting robots

Hope this may help you


Ok go to Remote Machine and kill uirobot.exe it’s holding license :slight_smile: I had it too and I fix it like this.

System exception or someone has logged in when it was working and interrupted process and by this robot couldn’t return to previous state - ready to work.

I checked it again. No help.

It didn’t help. I even restarted the machines. Btw, I reinstalled all Assistants but nothing changed. Then I modified the installer to bring Assistants in User Mode and it worked. Still don’t know what the problem is in the first place.

Check in the services if you have robot service on if not then start it