Failed to route the following signal

No routes are a little different than general no-fits. (I think of no-fits as the ones where the design uses more than 100% of the resources). What's the average and peak routing utilization? Some things that can cause this:

- High Logic Utilization but still below 100%. There's kind of a peak where a design might not use 100% but is unroutable.

- Low fitter effort. For example if you set the fitter effort level to Fast Fit, that can cause a no-fit.

- Large hold requirements(this is usually a mistake in multicycle constraints, where users enter multicycle -setup constraints but no corresponding -hold requirements.) In the fitter report look for "Estimated Delays added for hold requirement" (It's something like that.)