If you're looking for a free alternative, there are some open-source and free video converters available, such as HandBrake, VLC Media Player, and FFmpeg. However, these alternatives may not offer the same level of features and support as Xilisoft 3D Video Converter.
Regarding the "Serial Key Fix Free" part, I must clarify that using cracked or pirated software is not recommended, as it may pose security risks and violate intellectual property laws. Xilisoft 3D Video Converter is a paid software, and purchasing a legitimate license key is the recommended way to use it. Xilisoft 3d Video Converter Serial Key Fix Free