Resolved: WCAT: Invalid code received - Run error detected, terminating clients

When implementing WCAT for load testing for the first time I ran into the overly vague error message below.

All clients connected, Test beginning.
 Invalid code received.
  message: Run error detected, terminating clients...
  message: Terminating all instances of wcclient...
  message: Terminating all local instances of wcctl.exe...

Nothing I did seemed to let me get anymore information to help me zero in on the issue. After spending a significant amount of time troubleshooting, I started the client in one window using the command below

wcclient localhost -b

Then I opened a separate cmd window and ran my job using this command

wcctl -clientfile ubr\scenario.ubr -settingsfile ubr\settings.ubr

Obviously, you need to point to your files in their relative locations, but that's what I ran. The big thing, is that by running it this way, instead of through wcat.wsf you will actually see a useful error message. In my case, missing s semicolon on line 149.