Well, what do you think the error means? Why don't you debug properly?
To make it short, GetDataBySecureGUID
returns an empty array, so accessing index 0 is not valid.
Please change your code as follows:
var results = taOut.GetDataBySecureGUID(request.ToByteArray());
secReqOutRow = results[0];
Now set a breakpoint to the second line and inspect the value of results
. How many elements are there?
I bet there's none, because that's exactly what the exception means. You're trying to access an element in a collection using an index that is larger than the maximum allowed index. The fact that you're trying to access the first element and get this error means that there is no first element, so there is no element at all in the collection.