Window Application not runing at user end

[Arjun_Sarankulu]

My application is running fine on my end
Which also contain app.config file from which i am taking the connection string.
When i run the exe it gives error on user end
And if i hard code the connection string then its working fine on user end.
I am not getting what is wrong with app.config file

[abelLazm]

what error you get when you use app.config connection string?

[abelLazm]

Following are some common problems and their solutions. I think it will help you :)
-if the error is of invalid login then the problem is with your user-name and password check them on the system
-Another common problem which we face during the use of app.config files is Firewall.
-Please check which authentication are you using is it window authentication or SQL authentication. I think SQL authentication will work for you

[Arjun_Sarankulu]

Its giving error
Object Reference not set to an instance of an object
But its working fine in visual studio
And want i deploy at user end it gives the above error

[abelLazm]

Can You please give your connection string from app.config

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