We can create Asp .Net classes or bussiness objects inside App_Code or using compiled library .dll file in Bin folder.
Alternatively classes may be write inside WebService. If nothing is wrong then we can access our web app classes when it is launched via Visual Studio.
Unfortunately, after we deploy it to IIS and try to access deployed classes or WebService an error “Compilation error .. Type xxx is not defined ..” occurs.
Let’s make a New Website Asp .Net Empty Web Application to make problem and solution clear.