SharePoint Online Master Page and Site Inaccessible

Question

I created a copy of the Seattle master page and added a javascript link to the new copy. Now that I have activated the new master page I receive "Something went wrong error" and I cannot get access to the site. Every attempt displays the previous error? Any ideas on how to get it back?

Other info:

• Created copy of master via Designer 2013
• Published new master page via Design Manager in SP I think I changed both the site AND admin master page to my new page (that's probably what broke it!)
• I can get to the top level site collection page

Thanks for your help!

Answer 1

Answer was given here on TechNet . In short, from SharePoint Designer 2013 right click on the master page's .master file (not the .html file) and select Set To Default on the pop-up menu.