Missing Custom Tab on the New SubSite Creation Page

Question

I have a Publishing Site that I would like to create a template out of and use it across different Sites to create new Subsites basically it should be available across Site Collections.

Basically since its a Publishing Site I don't the get the option for Save As Template and I have looked around and not sure if using Designer is a good option to change the status of SaveSiteAsTemplateEnabled = True on Parameters tab

Second issue is I don't see the Custom Tab on the new subsite creation page.

Answer 1

For your first question, following explanation can be helpful to save a Publishing Site as a template.

Note: It is not recommend to save publishing site as a template, as the produced template will have errors and isn’t reliable to be used in production to create new sites off of.

Since the Save site as a template option is hidden from the publishing sites settings page we all used the following URL to go there directly:

/_layouts/savetmpl.aspx

Or

/_layouts/15/savetmpl.aspx

Well, that is not going to work anymore in SharePoint 2013 if your site is a publishing site or have the publishing features activated.

You basically get that following error:

The “Save site as template” action is not supported on this site.

In order to get around this issue you need to update a single property page value in your SPWeb object for the site you are trying to save as a template and you are good to go. The property is called SaveSiteAsTemplateEnabled. We need to set that property to true that’s all.

To do that using PowerShell:

# Get a reference to the target site
$web = Get-SPWeb http://Intranet.Test.com/Publishing

# Update the property bage value and set it  to the string value "true"
$web.AllProperties["SaveSiteAsTemplateEnabled"] = "true"

# Commit the property change to server
$web.Update()

Refer Save SharePoint 2013 publishing site as a template for more detail

Answer 2

If you are looking for "Choose your site template later...", its available while creating the site collection.

If you are looking for a other custom site template, it is possible that there is no site template under "Custom". Remember, your custom site template may be be marked to be meant for Root Web only (top level site). Run following PowerShell command and see which templates won't be able to create a sub site:

Get-SPWebTemplate | Where-Object {$_.IsRootWebOnly -eq $true}