I'm using the trial version of SmartAssembly v18.104.22.168, and is unable to use the gui interface to obfuscate .net 4.5 assemblies. SmartAssembly says that i have not installed .net 4.5. However, windows server 2012 r2 comes bundled with .net 4.5 and i can even run the assemblies! So i have .net 4.5, and when i tested SmartAssembly CLI, it worked fine! So it seems like a small gui bug... i even tested on windows server 2012 (not r2) and it still fails.