I know I have posted before about getting SalesLogix functionality running on a x64 based machine but I really wanted to reiterate the point. Yesterday I was working on a .net extension for a client and wrote a test harness for verifying some UI functionality. When trying to log in I was getting a ‘Provider not registered error’ .
I went to the properties of the harness application and changed the compile from ‘Any CPU’ to ‘X86’ and ran the second time and all worked as expected.

This is especially important for devs not running on x64. They won’t even know that an error is possible until a customer happens to run it on x64.
I always forget to change that 🙂