When you browse to the SharePoint Online or SharePoint Server Site settings page, you discover that the Save site as template option isn't available.
his issue most frequently occurs because the Community Sites Feature site feature, the SharePoint Server Publishing site feature, or the SharePoint Server Publishing Infrastructure site collection feature is currently enabled or was previously enabled for the affected site.
SharePoint doesn’t support creating a template from a site where publishing or community features were enabled. This is because the publishing feature creates site elements that are not supported as part of a template, and these elements remain even when the feature is disabled. This also includes templates that were created through SharePoint Designer.
Note Although the Save site as template option may become available after you deactivate publishing features, it is still unsupported to create a template from a site that has ever had publishing features enabled. If you create a site from this template, you may encounter problems when you try to activate publishing on the new site. For example, you may receive the following error message:
Provisioning did not succeed. Details: Failed to initialize some site properties for Web at Url: '......' OriginalException: Failed to compare two elements in the array.
In SharePoint Online, if you disabled scripting capabilities for the affected site, this also removes the Save site as template option. For more information, go to the following Microsoft website:
Although you can't use the Save site as template option in this scenario, you can use the app model to customize the provisioning process in SharePoint Online or SharePoint Server 2013. This lets you enable specific features, capabilities, and branding for your sites.