Re: Are my files lost forever?
The URL reported by Firefox itself looks suspicious because of the leading slash "/W:/Dep...". If that is indeed what Firefox reports, then maybe it is reporting incorrectly what should be "W:/Dep...". Use your file manager to check in that W: path for that specific file.
Another thing could be the use of the "()" or "&" characters in the filename. Check to see if the actual filename has them replaced by HTTP escape sequences (begin with the "%" symbol).
Looking to move SQLite Tools For RootsMagic from Wikispaces