Object reference not set to an instance of an object.'

This error message typically occurs in .NET programming when you try to use an object that has not been initialized. In other words, you're trying to call a method or access a property of an object that is null or does not exist.

To fix this error, you need to make sure that the object has been properly initialized before you try to use it. You can do this by checking for null values using conditional statements or by initializing the object before using it.

For example, if you have a variable named "myObject" that you want to use in your code, you can initialize it like this:

MyObject myObject = new MyObject();

This creates a new instance of the MyObject class and assigns it to the myObject variable. Now, you can safely use myObject without getting the "Object reference not set to an instance of an object" error.

If you're still having trouble identifying the source of the error, try debugging your code to see where the null reference is occurring. This will help you pinpoint the issue and make the necessary corrections.