Windows 10: Win 10 stopped playing music

I've made no changes to the system but suddenly am unable to play any music file and see the following notification

"signature is invalid. To register in developer mode, Appxsignaturep7X and AppXBlockMap.xml must be valid or must be present"


I don't even know what developer mode is! Help anybody???


I've tried system restore but it makes no difference.

:)

 

Where is the "stop" icon for a music album playing in a Win 8.1 phone?

I sync'ed a few music albums from a drive on my Win 8.1 computer hd to a Nokia 510 Win 8.1 phone and when playing back the album (thru headphones), there doesn't appear to be a "stop" icon to stop this music playing in the phone's music program. There are
"back" and "forward" icons, as well as "pause" icon....but no "stop" icon. Any ideas on how to stop albums from playing...they are on the onboard memory card after sync-ing from a Win 8.1 computer.

 

music stops playing when minamising the window.

As the the title when playing music on win 10, when I minimise the window the music stops playing and starts again after maximising it?

 

Groove stops playing abruptly

Groove occasionally stops playing a few seconds into a song when I double click a new track in Windows Explorer and an existing track is already playing.

Steps to reproduce

• Open the Music folder
• Double-click a track
• With the track still playing, select a different track from Windows Explorer
• Repeat a few times letting the track play for a few seconds before selecting another
• On occasion Groove will stop playing a track that has already started