Label File Entry Not Being Displayed

I've created a label file say LabelFile. In that label file, I've created an entry, with an ID of LabelID and Label of TEST.

I'm using @LabelFile:LabelID in a Label property. Instead of displaying TEST, it's displaying @LabelFile:LabelID. If I put something like @SCM:CalculateItemCost into the Label property, I do get the proper label. 

What am I doing wrong?