Problem importing an audio file.

I'm running Windows 10 and recently upgraded to Elements 15. I'm trying to make a movie using footage filmed on my iPhone 6, together with an audio file that I also recorded on my phone using the voice memo app.

I've downloaded the voice memo (twice) from iCloud drive and then tried to drag and drop the file into Premiere Elements. I get an error message saying "The importer reported a generic error.". The file is an ".m4a" file. I used to do exactly the same thing in Elements 12 without problems.

What am I doing wrong this time?

Thanks,

Natalie