Cannot run Firefox in Comodo sandbox

I have several browsers installed - Firefox 18. IE9 (32 & 64 bit)t Opera, Chrome and Pale Moon. All on a Windows7, 64 bit laptop.
All EXCEPT Firefox will run in Comodo sandbox!
If I look at the task manager after trying to start Firefox in the sandbox, it is shown as a running process, but no windows appear and to all intents and purposes it isn’t running!
Advice would be nice!
Ta muchly. :-*

It seems to be not working properly in Version 6, when I click on the Sandbox Firefox icon in the Comodo widget it can take up to 5 minutes for Firefox to appear. Then when I load in web pages it normally freezes.

it’s frustrated…in my case,it took me a while to figure it out because it stopped working then. so disable Avast script shield>> untick firefox/ie.

it worked for me. hope this will help