How to develop/debug scripts on gateway

i am following. but I got a weird error.
when using script transform (calling to project script) - I got no error.
But when using runScript(), calling to project script returned error.

I debugged. Seems the error is in project script line 111:
image

I don't know why runScript throws an error on line 111.

Attach is the project script..
TagMonitoring_Project_Script.zip (1.5 KB)
tagList format:

[
  "[default]Practice Alarming/Alarm Tag 1",
  "[default]Practice Tags/Expression Tag"
]