I am having the same issue of QBO crashing.  It crashes randomly multiple times a day, and sometimes multiple times when trying to complete the same task, which requires so much duplicated work.  I use Firefox and it is the most updated version.  I have tried incognito mode and it still crashes.  I have tried Chrome and Edge as well with the same issue.  Cache and cookies have been cleared. 

What the heck is going on, Quickbooks?  This problem has only existed for the last several months and I have been using QBO for 4+ years.  Obviously something is wrong on your end and it is not because of the user's browser.  This issue coupled with other "improvements" that were made to the invoicing template are causing me hours and hours of lost time.