Make sure the WMA files have a bitrate no higher than 320kbps and a sample rate no higher than 48kHz.

thanks for your response.  have played them under that rates in the past.  just this week it started happening.  the file i am trying to play is below both rates

Try rebooting your phone and the device where your music library is stored. Also try updating your music library in the Sonos app.

no such luck.

tried all.

even delete drive and copied to new drive and then linked that.  same issue

Play the problem track for a few minutes then send in a diagnostic. Contact Sonos support with the diagnostic number and let them look at your internal data to see if they cn find the issue.