Browser diseased with "non-responsive script" syndrome

[AaLF]

Firefox browser (channeled thru sandboxie) is plagued with script dramas on just about all websites e.g. Facebook, Youtube and so on. The pages do not respond until much time passes to alert me to a script problem, eventually forcing me to close the browser.

e.g.

WARNING UNRESPONSIVE SCRIPT
A script on this page may be busy, or it may have stopped responding. You can stop the script now, or you can continue to see if the script will complete.

 

[Not Myself]

This is the usual page for helping with this problem: Unresponsive Script Warning - MozillaZine Knowledge Base

However, I have no idea if sandboxing Firefox has any effect on non-responsive scripts. An obvious check would be to try running Fx outside of a sandbox.