Try the below fix for the freezing problem
1. Open firefox and in the address bar type in "about:config"
2. click on the button 'I ll be careful, i promise"
3. use the search bar located on the page to look for the 'network.http.pipelining' and double click on it to set its value to 'True'
4. create a new Boolean value named 'network.http.pipelining.firstrequest' and set that to 'True, as well.
5. Find 'network.http.pipelining.maxrequests' and double click on it. Then change its value to '8'
6. look for the network.http.proxy.pipelining' and set it to 'True'
7. create two new integers named 'nglayout.initialpaint.delay' andd 'content.notify.interval'; set them to '0'
8.now, restart your browser to experience the difference