I have a web application using CR XI R2 that has several reports which are pushed a dataset. These reports have been runing fine until today when I received an error stating "Database login failed." "Object reference not set to an instance of an object" in the report viewer control.
I recycled the application pool and the reports started working again.
My questions are:
What could be the cause of this and how can it be avoided?
Why does recycling the application pool correct the problem?