With the code below, everything compiles without any error. But when I run the resulting MSI, I don't see any site created in IIS:
<Wix xmlns='http://schemas.microsoft.com/wix/2006/wi' xmlns:iis='http://schemas.microsoft.com/wix/IIsExtension'>
<iis:WebSite Id='dp_service_site' Description='Default Web Site'>
<iis:WebAddress Id="AllUnassigned" Port="80" />
</iis:WebSite>
.
.
<DirectoryRef Id='DPDIR'>
<Component Id='dservice' DiskId='1' Guid ='21e0c49d-e9a6-4de6-894c-d0632ea45f5a'>
<iis:WebVirtualDir Id='dp_wvd' Alias="DocumentPublisher" Directory='DPDIR' WebSite='dp_service_site'>
<iis:WebApplication Id='dp_app' Name='Default Application' WebAppPool='dp_pool' Isolation='medium'>
</iis:WebApplication>
</iis:WebVirtualDir>
<iis:WebAppPool Id='dp_pool' Identity='networkService' Name='dservice' />
</Component>
</DirectoryRef>
.
.
<Feature Id='Service' Title='Document Service' Level='1'>
<ComponentRef Id='dservice' />
</Feature>
</Wix>
I am getting error. I have changed the code as per you have mentioned above. I have attached the screenshot along with this
I believe the issue here is that you are not creating the WebSite within a component, so instead the installer is just trying to do a lookup for an existing website. Instead you should probably have something like this:
So then the website will be created as a separate component. I believe that since you have specified a port number, if a website already exists on that port then it will modify that existing website instead of creating a new one.
UPDATE: As the error indicated, you need to add a Directory attribute to the WebSite element pointing to 'DPDIR'. I have updated my example above.