No validation error in case of unexisting external executable path in command line tool

Scenario:

1. Open the Workflow Designer.
2. Click the "Create element with external tool" button.
3. Set "Executable path" to a nonexistent path, e.g. "D://blabla.exe".
4. Follow the wizard until the complete element creation.
5. Run the workflow.
   Current result: There is no any validation error on the workflow launch. There is "The workflow task has been finished successfully!" status on the WD dashboard while in the log there is a line about the missing tool:

   Can't run an executable file "D://blabla.exe" as it is. Try to run it as a cmd line command: "cmd /C D://blabla.exe"
   

   Expected result: the workflow is not launched. There is a validation error in the errors list:

   [The element name]: The element specifies a nonexistent path to an external tool executable.