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Originally posted by: stonysmithThe color(s) of the pins tell you specific things:
White: Has not been executed (no temp file exists behind the pin)
Yellow: The node is executing, and a partial temp file exists
Green: The node is finished and all of the temp file is available to downstream nodes
Red: The pin is not connected to a node that will ever produce any data.
Orange: The pin is downstream from another node that has a red pin (see above)
In this particular case, the XREF itself is another composite - open up the XREF and look inside of it.
You'll find that the output pin is disconnected, or that it is connected to some node that has been disabled.