I am trying to play a sound when paused - which i have achieved by ticking the ui sound in the sound class. However after i unpause the game the sound continues, i need it to stop. so when menu widget is active it starts an when widget is removed it stops etc. Cheers! 
Can you tel me how did you remove your widget? If you use a button click event, that maybe a good place to include the code to stop the music.
i have a continue button that un pauses the game, its done with blue prints
Have you tried to put the code to stop the music here mate?
I have tried but i don’t know what to put in to stop the certain music file.
Try to use audio component in level.
I have a problem with the audio, which when the game pauses for a few seconds the sound stops instead of pausing and returning from where it left off.