For troubleshooting ACE calculations in run-time, it is best to use calls to method PIACEBIFunctions.LogPIACEMessage to write custom debug messages to the local PI SDK Message Log.
If you need details on how to use this method, check the PI ACE Reference in \Program Files\PIPC\ACE\Help\PIACEReference.chm
In general, "Calc Failed" appears when the value for the output tags remains uninitialized for whatever reason, typically when some exception is raised during the execution of ACECalculations sub.
You may also want to take a look at this Technical Support Knowledge Base Article for more information.
Please keep us posted on your findings.
Thanks Daniel. Your input helped.
I was able to determine after wrapping the logic with a try/catch and writing to the PI log that the program was unable to find the config file. It was looking for it under the windows/system32 folder vs. relative to the DLL location where I would of thought it should be.
Thanks for closing the loop, Steve!
I'm glad you found out what was causing "Calc Failed".