Export error Premier Elements 2019 with audio from outside Adobe Elements, works if I delete audio

[newbie5]

My Adobe Premiere Elements 2019 was working great until recently when it all of a sudden gives me an "Export error: Error compiling movie. Unknown Error". If I delete the audio, it works. I can edit everything fine but when I go to export, I get the error. It didn't do this before. I've tried using different video clips and audio formats but it still does it. The only audio it will actually let me export is the "built in" audio in Premiere (which is extremely limited). I have a Windows dual core i5-8500 processor with 8GB ram. Can anyone help?

[Bill Sprague]

What is the audio source and format?  

[newbie5]

Any time I use .MOV video clips from ` Ipad, it won’t export until I delete the audio. It also won’t export any time I add .mp3 or .m4a soundtracks from my hard drive. However, I just discovered it will export video with audio if I use .mp4 movie clips. It’s just frustrating to not be able to add any of my own music.

[Bill Sprague]

If the .m4a sound tracks are from iTunes it is likely they are "copy protected" to prevent their use.  Apple does that.  The .mp3 files should work better.  Depending on the source, they may also have copy protection built in.   

I have a small collection of .mp3 files that were intended to be used for video making.  Some were free and some I had to pay for.   

Some people have written here that .wav files are the easiest to work with.  It might be possible that you can convert your files to .wav with a third party converter.  

[popto]

I'm having the same issue for the first time. I'm editing green screen video (recorded with iPhone 11) for the first time to. Can anyone help me troubleshoot this issue?