Hi Steve,
OK back to the original issue...
Have you tested the sample?
1525014 - Sample C# .NET UFL and Localization Formula function
Can you see the functions and use them?
I confirmed this sample does work when built in VS 2013 and setting the CR Designer Config file to 4.0 Framework as noted earlier.
PS - update the data source for the test report and use the Xtreme.mdb
DOn