Hello,
Since many of us are leveling new chars to benefit from the currently on-going levelling event, I'm sure you have noticed that avatar weapons are not critting as they used to do in the past, and I think I've found a (temporary until fixed?) solution for it and that is by simply re-equipping your avatar weapon once you enter a dungeon.
Here's a short video where I use level 44 avatar weapon in Necromancer's Tomb (Monsters are 43 there), I take off crystals first to not overkill mobs too much, then attack a couple of mobs before re-equipping the weapon.. Just pay attention to the damage log to the left and you'll notice the amount of non-critical hits. Then I get out of combat, take my weapon off, put it back on and boom.. Crits are suddenly working again. :^)
https://www.youtube.com/watch?v=40lZj5U2XRU&feature=youtu.be
Enjoy levelling, ladies and gents.