Likely a codec issue. Try first converting the audio file to WAV or Mp3, then import that file into VP. You might even try converting the audio in VP itself, which would result in a WAV file that could be dropped onto an audio track. Right-click the file in the media bin area (top-left).
If no joy, upload your .WEBM to a server (Google Drive, MS OneDrive, etc.) and paste a public link here. Someone will check it out for you.
