ASP.Net App_Code folder classes
The Classes that is getting put to this folder is not getting accessed from outside this folder. You might be wondering why this happens. The answer is simple. It doesn't get compiled to the DLL in the bin. If you right click on the class and go to properties window you will be see an entry called "Build Action". This is set to content which causes the issue. If you change this dropdown value to compile then your issue would get solved. But please keep in mind there might be issues doing this also.