Failed to route the following signal

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Attach your .fit.rpt and I'll take a quick look(2 minutes). Note that routability is not purely a function of how many LEs a design is. A giant shift-register is trivial to route, but if the whole design was a cross-bar mux, it's extremly difficult. Most designs fall somewhere in between. Is your design one of those where "everything talks to everything", or are these 6x1681 blocks pretty serial in nature(the output of one feeds the input of the next one, etc.)

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pls find the attached. thank you !