try clearing the cookies too?

and maybe try a different browser or restart the one you're currently using.
and make sure the adobe flash is upto date as well.

We did several security updates today and also some patches + new version.
If you still can't access it, I'd recommend you to clear all cookies and cache again and maybe even try out another browser. It seems that your cache still keeps the previous version.



edit: life was faster

Also remember that flash stores cookies differently than your browser cookies.

Have you tried running it from different websites? (probably won't work, but if you've tried everything else, why not give it a shot).
Supermechs.comNewgrounds one.

And just to double check you deleted the flash cookies properly, did you do this:
>Right click on the game, choose 'global settings'
>'Storage' tab >'Local Storage Settings by Site' button
>Scroll down to 'supermechs.com', select it, then choose the 'remove' button