Automation Copy File doesn't allow for Variable in Folder name for 3.1

[greg.nelson_640]

I just upgraded an automation script from 2.7 to 3.1, and the job is failing due to the Copy Activity. It has worked fine for almost a year in 2.7, but now in 3.1 I'm getting a build failed error when running the script. In the File Activity it will no longer let me use a variable to create a folder. The error is displayed in the attached image.