These messages mean that for some reason, some orders couldn't be reached.
For unreachable, this could occur because of the curb approach property or some restriction such as height, weight, or other violations.
For the violated pair, this typically means that due to routing constraints, you can pick up but not deliver a person or vice versa. You either don't have enough time or capacity usually.
For unreachable orders, you could provide us with the address and identify the dataset you're using and we could have a look and see if anything obvious is preventing it from being reachable.