Hi Jon,
I suggest you contact the makers of that barcode font and UFL and ask them if it is supported in VS 2012.
The error is being generated because it can not find a dependency for the barcode of UFL. It actually has nothing to do with the u212.com dll. It's just the dll reporting the error. Not sure if we can add better messaging, typically though it's the source that is reporting the error and if CR can it will pass it along. I this case though I suspect there is no message coming from the UFL dll to indicate what the problem is.
Not sure if I have the package from 3D Com but if I can find it and if I have time I'll do a quick test also but that will just validate there is an issue.
Make sure the fonts and UFL are installed also under the same account IIS is running under. Could simply be IIS does not have access to the UFL or fonts.
Try searching for UFL and IIS or Web server. I'm sure this came up before....
Don