Error appeared while working on Mozilla Firefox

Hi,
Just the other day, one of my users was working on Mozilla Firefox. Everything was running smoothly, but all of a sudden, the following error appeared on my screen:
An error occurred
The error was reported with the following id: 'Ih2hS19bXnpycHhe2Pq4'
Please send this error message to us:
'Errorld: In2hS19bXnpycHhe2Pq4 UserAgent: Mozilla/5.0 (Windows NT 6.1; rv:9.0.1) Gecko/20100101 Firefox/9.0.1 io is not defined in http://cjdns.thefinn93.com:9001/minified/pad.js?callback=require.define at line 9'
This is a very strange kind of an error I have ever seen. Anybody has any idea as to what went wrong in my system? Your helpful suggestions are needed please. I have searched a lot about this error, but I couldn’t find anything useful.
Looking forward to your replies.
Regards.
