Installing extension in Firefox 47 caused tons of spam lines

I tried installing a favorite extension in Firefox 47 (Classic Theme Restorer), and immediately was inundated with multiple lines spammed per second continuously. (This did not change even after removing the add-on and restarting Firefox.)

All the spammed lines were the following exact line over and over:

(ntoskrnl/mm/ARM3/section.c:2035) Warning, not handling dirty bit

I also got the same spam on build 74006 when the OS froze and I had to restart - upon opening I discovered Firefox lost all data saved in preferences and spammed continously even after I told it to close the browser.