Why do I receive the error message "ClassFactory; cannot supply requested class error" when playing files with RealPlayer?

When you play files on your computer, a "ClassFactory" error appears if the software (a codec) used to play the video is not installed. Codec is short for Compressor/Decompressor, a mathematic equation used to compress and uncompress data files. It serves as the interpreter that turns the computer code into sound and video.

Audio and video files are compressed using a codec. Codecs plug into the RealPlayer, allowing you to watch or listen to the file. Without the proper codec, RealPlayer cannot play the file. Read more about codecs.