Here is the problem: I have a Person Class:

And, I want to add a List<Person> type WF4 Variable peope to sequence, just like this:

Solution:
Step 1.Select Browse for types... in the Variable type list.

Step 2.

Step 3. Navigate to Person class and select it.

ac31ae7c-a84c-4990-a8e2-89f15bfb8ca5|0|.0
WF4