Can you post his daily routine? Sometimes a bit of tweaking there can help. With us, it was just a phase Tyler went through. It started around 20 mo and has continued off and on since then. He'll go for a couple of weeks of napping off and on, then a couple of normal weeks. If he chooses not to nap, that's fine, but we enforce quiet time in his room for at least an hr (easy since he's still in the crib, but if yours isn't, it can still be done). We did the exact same thing for the crying...in and out, in and out. It helped us a lot to have a "goodnight phrase" that we always used to settle him. When he cried, we'd try to verbally reassure him from outside the door first with the phrase (for us, it was just "night night, Tyler"). If it didn't work, we'd let him see us in the doorway and repeat the phrase. If he still wouldn't settle, we'd go to his crib, lay him down (if needed), rest a hand on him for a few seconds, and repeat the phrase. Then leave as soon as he settled. It was just a phase, and he got past it. Be sure to post back with his routine, sometimes there's an easier fix there!