"Unexpected character encountered while parsing value" error after upgrading to 18.1

This error may occur when you are trying to run a workflow after upgrading to 18.1 version without “killing” UiRobot.exe from task manager before the upgrade or you have installed both 2017.1 .msi and 18.1 .exe


  • Uninstall the 2017.1 version(if you have it)
  • Kill any UiRobot.exe processes from Task manager and run again from Studio. Please note that the updated Studio and Robot will be in this folder: %localappdata%\UiPath\app-18.1.1 under the names UiStudio.exe and UiRobot.exe
  • Uninstall UiPath Studio/UiPath Platform and reinstall