Error "There Was An Error Connecting To Terminal Error Code EhllDllNotFound" While Connecting To The Terminal Using Terminal Session Activtiy

How to troubleshoot error "There was an error connecting to terminal Error Code EhllDllNotFound" that occurs in Terminal Session activity while executing the project?

Root Cause:

While using IBM EHLLAPI provider option in the Terminal Session activity, if the dll path mentioned in the EHLL dll property is not found, this error is observed.


  1. To avoid incompatible dll path being used (i.e 32-bit EHLL dll used in Windows project), Please make sure UiPath project compatibility is same as the target terminal emulator [About Automation Projects].
    1. If 32-bit Rocket BlueZone is installed in the machine, develop the automations using Windows-Legacy project as it supports 32-bit process execution.
    2. If 64-bit IBM Rocket BlueZone is installed in the machine, develop the automations using Windows project as it supports 64-bit process execution.
    3. Alternatively, upgrade the UiPath.Terminal.Activities version to 2.6.0 or greater that supports both the bitness (32 and 64-bit) in Windows-Legacy and Windows projects.
  2. Ensure the dll path entered in EHLL dll section of Terminal Session activity (or passed in the Connection string using variables) is valid and the file exists.
  3. Check if the Robot user has access to the dll file and\or folder that contains the dll.
  4. If the terminal emulator installation folder contains different dlls (ehlapi32.dll, pcshll32.dll, or winhllapi.dll), test the terminal connection with each one of them to find the one that is compatible to the host configurations.