title: Why am I getting an 'Invalid Parameters' error when the generic type constraints are the same?
body: <p>In the code below, I am getting an error at 'action(u)', "Invalid Parameters", even though the type constraints on the generics are the same. Why is that and what can I do?</p>
  
  <pre><code>        public class Test&lt;T&gt; : IDoStuff where T : SampleA
          {
  
              Action&lt;T&gt; action;
  
              void DoStuff&lt;U&gt;(U u) where U : SampleA
              {
                  action(u);
              }
  
          }
  </code></pre>