UiRobot run via command prompt

I try to run UiRobot in RDP via command line execution. But it shows below an error.
cannot create unknown type { http //schemas.uipath.com/workflow/activities} SendMail
I already installed package MailActivity. The solution working fine in UIStudio and UiRobot.

UiPath version : Studio 2018.2.3

Do you see your excel activities installed under C:\Users\AppData\Local\UiPath\Activities\UiPath.Excel.Activities

I hope you are trying to run the bot in the same RDP where the UiRobot & Studio is installed.

Rammohan B.