Miscellaneous Tips for installing MEP 14
For more information, read this thread.
Choose Help>Activate Additional functions... Activate Dolby Digital Stereo Decoder (if you want the AC-3/Dolby Digital 5.1 ENcoder, you'll have to pay for it).
Note: With previous versions, it had been recommended that an external AC-3 decoder like "AC-3 Filter" be installed because MEP couldn't decode AC-3 audio. I have noticed however that with some HD files, notably from my TV tuner card, installing the AC3 Filter will not help, and the only way to get MEP to open the AC-3 audio was to activate the decoder through MEP as described above. Fortunately, if you do try to open a video with AC-3 audio that requires the decoder, MEP will pop up the activation window.