[How To Create A Vast Tag Using Revive Adserver?]

hi , i have tried this vast tag but there is an error showing up while loading ad. can u please help me

error:

jwplayer.js:2 Uncaught (in promise) TypeError: Cannot read property 'provider' of null
    at l.chooseProvider (http://localhost/jwplayer7.7.4/jwplayer.js:2:2441)
    at l.setProvider (http://localhost/jwplayer7.7.4/jwplayer.js:2:2985)
    at l.setActiveItem (http://localhost/jwplayer7.7.4/jwplayer.js:2:2881)
    at a.f.load (http://localhost/jwplayer7.7.4/jwplayer.js:5:11732)
    at http://localhost/jwplayer7.7.4/jwplayer.js:5:7272