NullPointerException when accessing portal imported from EPP 5.1.x in EPP 5.2.x with Site Publisher

Issue

When accessing a site exported from EPP 5.1.1 and imported EPP 5.2 with SP, we have the following error:

ERROR [org.exoplatform.webui.application.portlet.PortletApplicationController] (http-172.29.1.44-8080-7) Error while rendering the porlet
org.exoplatform.groovyscript.TemplateRuntimeException: Groovy template exception at DataText[pos=Position[col=1,line=28],data=  boolean userCouldEditPage = uicomponent.hasEditPermissionOnPage();] for template app:/groovy/Toolbar/UIAdminToolbarPortlet.gtmpl
...
    at java.lang.Thread.run(Thread.java:662)
Caused by: java.lang.NullPointerException
    at org.exoplatform.wcm.webui.Utils.hasEditPermissionOnPage(Utils.java:845)
    at org.exoplatform.wcm.webui.toolbar.UIAdminToolbarPortlet.hasEditPermissionOnPage(UIAdminToolbarPortlet.java:54)