Installing Firefox on EC2 using Lambda Linux Project

I'm trying to set up a nodejs+selenium server on ec2. I got node installed and working and I tried to set up Firefox using the tutorial here: https://lambda-linux.io/blog/2015/01/28/announcing-firefox-browser-support-for-amazon-linux/ I got it all installed but however, whenever I run firefox, I get this error. >GLib-CRITICAL **: g_slice_set_config: assertion `sys_page_size == 0' failed Anyone know how I can fix this? Thanks!