Currently, I cannot use Paypal Pro on my host (GoDaddy) because it requires Full trust level. After digging in Google, it seems a workaround is possible by adding AllowPartiallyTrustedCallersAttribute to the Paypal assembly. I have seen code samples that use AllowPartiallyTrustedCallersAttribute in their AssemblyInfo.cs file, however, I've yet to run into a code example that also happens to be using PayPal. My question is where should the AllowPartiallyTrustedCallersAttribute be added in my project if my objective is to make the PayPal assembly work? I have tried adding it to my AssemblyInfo.cs for the project that contains the entire website, but I have not been successful. At this point, any insight or shot in the dark would be greatly appreciated. Even if someone could point me in the general direction of some documentation I would be grateful. AllowPartiallyTrustedCallersAttribute Reference: http://msdn.microsoft.com/en-us/library/system.security.allowpartiallytrustedcallersattribute.aspx