A problem that is caused when a file is corrupted or something suddenly stops functioning.
Is this your first time playing Cross Fire? If so, I recommend you try reinstalling. Don't use torrents or the "mirror" sites it gives you, use the official Cross Fire Downloader. During the installation, disable anti sort of firewall, online shield, file checker, etc. During the installation make sure there are absolutely no programs in the background that are being a bother(downloads, music, etc).