When I build BlogEngine project, I got this error:
"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."
That error typically indicates that you have not marked your website as an application in IIS. In IIS, right-click on the folder containing your site in IIS and "Convert to Application" (or the equivalent in your version of IIS). Add it to the application pool that is appropriate for the version of .net that blogengine is running.