neo4j app does not work on heroku

i have a issue in my project It is based on nodejs , and using neo4j graph db as database I developed it and uploaded to heroku It worked well and i add to login function into app It works well on localhost , so i uploaded to heroku again , but then it does not operates now I added express-handlebars , express-validator , connect-flash module I can not understand why the app does not work on heroku , instead of it works well on my localhost If you have methods to solve this , then please reply me

thank you regards

via itbeckham7