There are 3 types of problems with site preview in Plesk:

1. Site Preview in Windows Plesk will show 404 Page Not Found error
2. Site Preview in Windows Plesk will show Plesk Default page.
3. SitePreview will ask for user name and password.

We will troubleshoot each problem with site preview one by one.

1. Site Preview in Plesk will show 404 Page Not Found error.

Cause: This happens if the sitepreview ISAPI DLL is not loaded correctly in IIS web server.

Troubleshoot steps:
a. First check if a the Virtual folder with the name sitepreview is create in IIS Default Web Site. If it is not created then create it without the application pool and map it to folder “%plesk_dir%isapi”, same as in image below.  Also Make sure that Executable Permissions are set to “Scripts And Executables”

b. Make sure that the Site preview ISAPI DDL is Allowed in Web Exteniosn and look like in image below, if not then Add it in Plesk Extensions.  

c. Also make sure that the Site Preview ISAPI DLL has been loaded with green Arrow in IIS >> Web Site >> Right click >> Properties >> ISAPI Tab. like in the figure below. If it is not loaded then just click on the Add button and browser through “%plesk_dir%isapisitepreview.dll” and restart IIS.

d. If you have IIS7 on Windows 2008 Server then make suer that you have Plesk Site Preview DLL added in IIS >> Click on Server >> IIS Group >> ISAPI Filters.

2. Site Preview in Plesk will show Plesk Default page.

Cause: Related to IP configuration on the server.

Troubleshoot steps:

a. Please fo through all the steps in problem one for this. However the only reason for this problem that I have found is main IP address of the server. Just make sure that you have alleast one site added on the main IP address of the server. To know the main IP address of the server Go to START >> Control Panel >> Network Connections >> Right click on main network adapter >> Click on Properties >> Select TCP IP >> Properties. The IP address list in this windows as IP address is the main IP address of the server. Just make sure that you have atleast one site hosted on this IP address.

The above solution will also apply is Plesk Site Preview option is working with https prefix butnot with http in URL browser.

3. SitePreview will ask for user name and password for all website.

Cause: Related to Permissions and Security Options.

Troubleshoot steps:

a. First check if the URL work fine with the IP address only:

http://192.168.1.52/

if not then there are permissions issue with the default site and if you are using a dedicated IP address instead of shared IP then the problem is with the permissions of the site that holds the dedicated IP.

b. If step “a” is working then try access the link below:
http://192.168.1.52/$sitepreview/

The above link should get redirected to the IP address and show Plesk default page or index.html page in Default Web site but it is is asking for password then permissions on sitepreview virtual directory is not correct. Make sure that IIS_WPG, NETWORK SERVICE, psaadm, psacln & psaserv has read an execute permissions on the virtual folder, do not forget to inherit the permissions to files in it.

c. If it asks password for only one site then the problem should be either with the website permissions or the file you are accessing it.

I think this should cover all the problems with Parallels Plesk Site Preview problems. But if you still face problem and don’t want to use Site Preview then you have try the HACK below.

WINDOWS HACK TO POINT YOUR SITE TO AN IP WITHOUT CHANGING THE NAME SERVERS.

So here we go:

On your local machine, [AND NOT THE SERVER]:
Goto START >> Run >> and Type:
notepad "C:WINDOWSsystem32driversetchosts"
And hit Enter

If you get file does not exist error then create hosts file in notepad “C:WINDOWSsystem32driversetc” folder.

At the end of the file you will have:

127.0.0.1 localhost

Just add your domain with the IP you want to point to, and it will look like, this will be also applicable if you have create a new hosts file:

127.0.0.1 localhost
192.168.1.52 mywebhostingblog.net
192.168.1.52 www.mywebhostingblog.net

Save the file and exit.

Now ping the domain on the computer you have made changes on and it will point to the IP address defined. You can now browse your site without the site preview and you will have to the content of the server you are moving to. Just remove the entries from the hosts file to point your domain back it was.

Wasn’t that Simple..!!!