I do not seem to understand correctly your problem. Did you record from the Presenter plugin (see screenshot) when having the issues or did you try to import MP3-files? If you are recording, there is no need to convert yourself, you get automatically MP3 files that will be stored in the data-folder. What is exactly the error message that you get?
Yes, I have recorded from the presenter plug in. Whenever I hit publish after finishing up, or even if I go back to the "home" portion of powerpoint after narrarating a few slides, when I try to go back into the recorder, The error message reads ... "Adobe Presenter cannot load the recordings for all slides. The recordings are not in the .ppcx file." "The recordings were last stored in this file" .... it then gives the file name ending with /Media.ppcx. It then gives options including "load the recordings from another file." When I hit browse, it has empty folders. I have the MP3s ... but it will not let me search for those to import. Instead it has it set to the .ppcx. The actual folder has my presentation name on it, but no audio. The other option is to "continue without the recordings on the slides, which erases the audio completely ... even from MP3s. The other option is to cancel and return to the slide show. I have no idea what to do!
Wow, I would love to know how this problem was resolved, and what causes it to happen in the first place! I
have had this happen a number of times and it is extremely frustrating.