Could anyone tell me why this does NOT work...

Data.ExecuteAggregate is a function that will return an object. I cast it to an int but errors out with "System.InvalidCastException: Specified cast is not valid."

The altered code below DOES work though...

I've tried to look for limitations with casting but have not found any.

Thanks in advance for your help!

When you use Convert.Toxxx it coverts it to a .NET datatype. (int) converts it to an Integer datatype in C# if I have read correctly.

From what I have experienced... You can cast from similar types. So in this case you could cast from a double, single, float, etc to an int. But if you want to convert (note the keyword) you need to use the Convert class methods like you have found.