A couple of technical questions

I am using Tor with Prixoxy. What does this message mean?

www.xxxxx.com/net/org has sent an incorrect or unexpected message. Error Code: -12263

I once asked about it somewhere else, but I have forgotten the answer. Besides I did not believe their answer.

The second question: I am using Firefox. When I try to save a page ("Web page, complete") Firefox sometimes opens a box and says: "Starting download". This starting seems to take an indefinitely long time, and when I check my disk later, nothing new has been saved there.

I did not have this problem before Tor.

Please answer.