Not to worry :) The solution to this isn't really difficult and we can fix this problem by following these few simple steps as mentioned below:In the Firefox address bar, type about:config and press Enter.
You would probably get a certificate stating: This might void your warranty! You can ignore that message this time and click on the button: I'll be careful, I promise!
The following page would open up:
In the filter box, below the address bar, type: dom.max_script_run_time and press enter. The details of the preference name dom.max_script_run_time would open and the remaining entries vanish, which makes it easy to work through.
Double-click on that entry and change the default value which is given as 10, to something higher. I changed mine to 1000. You can also comfortably change it to that or experiment with something that suits your requirements.
Click OK and restart Firefox never to see that warning message every now and then!