Question

I have a Asp.net-C# Web app, with 4-5 associated projects all written in c#. I’m using .net 3.5.

My problem is, when I try running my application from the solution, it shows an error:

“Error 17 Object reference not set to an instance of an object”

When I build/rebuild the solution, it will be gone. When I click the error it takes me no where. And another interesting thing is, there is no location specified for the error.

Please help.

Answer 1

The error means that some object is null, and you try to call a method or access a property on it.

For example this code will give the same error message:

string myString = null;
int length = myString.Length;  //gives error since myString is null

If you can’t find out where, and for some reason don’t have any stack trace, try adding a try/catch block around the code you think is suspicious and see if the error is there or not.

Another solution is to just add a breakpoint, and go through your code line by line untill it explodes.

Without more details, that is the best advice I can give you.