So I'm having this strange issue with Mozilla version 52.4.1. I'll first explain what's supposed to happen (it works, for example, on my version 45.7.0). I formatted this question as best as I could to make it easier to read and understand. INTENDED FUNCTIONALITY: I have a web application I developed, and it contains many tables filled with information about people (purposefully vague here so if you need clarification, please let me know). Each person has a row to themselves. It has been developed so that the user can edit any person's information in the table by clicking a small "edit" link next to their row. Once you click it, it should briefly open a blank new tab and THEN a new window and THEN automatically close the blank tab it just made WHILE leaving the new window open (this new window contains other stuff necessary for the user, i.e. it's not blank). This happens very quickly and is almost unnoticeable. So currently, the INTENDED FUNCTIONALITY works with Mozilla Firefox 45.7.0. However, this is the PROBLEM that occurs with version 52.4.1. PROBLEM: When you click "edit," a blank new tab opens and then the new window opens (as intended) BUT THEN the blank new tab remains opened. I don't want the user to have to manually close it every time. Why is this happening and how can I fix it? Any help will be greatly appreciated. Please don't hesitate to let me know if any clarification is needed.