0) Start by using Google Chrome
1) Patch Liferay DXP 7.1 with FP20 and hotfix-5047-7110
2) Add the below in portal-ext.properties:
then, start the server, login as an admin
2) Create 2 new blank sites, e.g. "site stag" and "site remot"
3) Follow this article to activate Remote Staging using the same Liferay instance: https://help.liferay.com/hc/en-us/articles/360030700452-How-to-simulate-a-remote-staging-environment-with-one-portal
4) Create a new user and make it Site Administrator of both "site stag" and "site remot"
5) Go to "site stag" and add one Public Page
6) After adding the page navigate to it and, on top-right corner, click on the wheel icon
7) Go to the "Advanced" tab and expand the accordion menu for "Customization settings"
8) Set "Customizable" to "Yes" and switch the radio button to "Customizable" on all the "column" areas that will pop-up underneath
9) Logout/login with Site Admin user and go to the staged page create at step 5
10) Click on the top-right "+" icon, add portlets on the customizable areas, assert all works and that the browser's console gives no errors
11) Now, repeat step 10 on IE11:
Expected: Same result as on Chrome
Actual behavior: The browser's console prints: