I have an executable that works OK. When I run the source code using the same web.config file, I'm getting an error message
It is an error to use a section registered as allowDefinition='MachineToApplication' beyond application level. This error can be caused by a virtual directory not being configured as an application in IIS. It's pointing to line 53 in web.config. Line 53 says:
The machine on which I have the source code does not have IIS, but the program has worked before. A recent change was to enable anonymous authentication in addition to forms authentication.