Try restoring your DSAce.dll file, or do a complete reinstall of Freelancer and Disco (take a backup of your accounts first). But before starting up Disco or anything, after you reinstall completely, add an exception to all the Discovery related folders like the My Documents folder, vanilla install folder and the Disco install folder. This should mostly work. Or try opening your newly installed Disco after disabling your antivirus. I had the same problem once, and this helped me, since the antivirus deleted DsAce.dll and some other files. I reinstalled, added exceptions and it started working again.
