The problem here is that you cannot make a cyclic graph. Imagine a patch like this:
The + node here needs both inputs to calculate its output. But its input is dependent on its output, because it’s a cyclic graph! The graph can’t resolve, the program wouldn’t make sense anymore, so vvvv doesn’t let us connect cyclic graphs.
What you can do is make the input of the + node dependent on its output of last frame. That way the plus node will have both inputs available to calculate the output, since what it needs was already calculated last frame. A FrameDelay nodes lets you make such ‘cyclic graphs’:
This patch will now count up in steps of 5 every frame.
Same applies for the TCP node, put a FrameDelay between your output and input.
Watch out when using framedelays though, and use them only when you’re sure you need to and you know why. Building this, for example, will break your patch:
because it will make huge spreads, after a few minutes too big to store.
Also, when posting patches on the forum, try to make your question easier to answer by creating the smallest version of your patch that still has the problem. For your question, this would have been enough: