Java Script Error

I have a Mac Os X with a 3.2 GHz Processor and plenty of Memory and Ram. Whenever I download the ChoiceScript and try to open the file with firefox. It says there is a javascript error:

"Couldn't load URL: scenes/startup.txt
Error: NETWORK_ERR: XMLHttpRequest Exception 101”

I tried to open with safari, no luck. What is the next step of trying to fix this problem?

Thanks,

Sefra