A month back I was implementing online payment in my project.
While doing so I faced many barriers. Thanks to google and of-course StackOverflow I was able implement it successfully.
But recently(a week or two maybe) things changed. When I tried opening the site, as soon as you click enter, it was showing error. Don't know what error it showed back then but its one among the errors im going to furnish below.
So I tried creating the same project once more in visual studio. I put reference to the third party dll file, put identity impersonation="true" username="" password="" in web config and almost everything and made sure no build errors occur. I created a deployment package and inserted it into the site folder. I encountered the error 
Next I made a deployment package and deployed it in wwwroot of my PC converted it into web application and then uploaded it into hosting site folder. Then I encountered such an error
I searched for a day or two applied many things but was not able to get out of this problem.
Later I simply tried deleting contents of web.config. I first tried with . It did let me get the page but then when I click a button it access a file in the in server that could not be accessed. So I let identity impersonation="true" be there and removed username and password. It worked but only problem was it asked for username and password when I click that button. I provided the username and password I provided in the web.config and it did work.
I don't understand why but it seems that the web application doesnt work when I provide username and password in both the cases I mentioned above. And when I remove username and password from it it prompts me for the login credential.
I want to make it in working condition in a day or two. Any idea what might be the problem???
