Page Editor is unavailable in staging site

• Type: Bug
• Status: Closed
• Resolution: Fixed
• Affects Version/s: 7.3.5 CE GA6, 7.3.X, Master
• Fix Version/s: 7.3.10 DXP FP2, 7.3.X, Master
• Component/s: Page Templates > Master pages, Staging > Export/Import
• Labels:
  • ee-ts
  • liferay-fixpack-dxp-2-7310
• Branch Version/s:
  7.3.x
• Backported to Branch:
  Committed
• Fix Priority: 4
• Git Pull Request: https://github.com/pavel-savinov/liferay-portal/pull/657

Step to reproduce:

1. Add a new site
2. Add a custom master page
3. Add any fragment to the master page
4. Publish Master
5. Add a content page based on custom master page
6. Publish the content page
7. Enable Local Live
8. Navigate to Pages admin in staging site
9. Click the ellipsis button of content page > Edit

Expected Results:
The page editor should be available.

Actual Results:
The page editor is unavailable. Additionally, the following error is shown in server console.

2020-11-27 10:37:08.062 ERROR [http-nio-8080-exec-7][render_portlet_jsp:131] null
java.lang.NullPointerException
        at com.liferay.layout.content.page.editor.web.internal.display.context.ContentPageEditorDisplayContext._getFragmentEntryLinks(ContentPageEditorDisplayContext.java:1416)
        at com.liferay.layout.content.page.editor.web.internal.display.context.ContentPageEditorDisplayContext.getEditorContext(ContentPageEditorDisplayContext.java:569)
        at com.liferay.layout.content.page.editor.web.internal.display.context.ContentPageLayoutEditorDisplayContext.getEditorContext(ContentPageLayoutEditorDisplayContext.java:141)
        at org.apache.jsp.view_jsp._jspService(view_jsp.java:244)
        at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:111)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:733)
        at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:411)
        at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:473)
        at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:377)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:733)

Reproduced on:
Tomcat 9.0.37 + MySQL 5.7. Portal master GIT ID: 5aceff3ec63a5118178d7967f0903964b769a773.