Can't trade with villagers

Same problem. I opened a saved game from 1.14.2 in 1.14.3. The trade screens worked correctly in 1.14.2 (I think, but I know worked in 1.14.1).

I also think possibly I've traded with a wandering nomad in 1.14.3 and it worked, but I could be thinking of 1.14.2.

When you click on nitwit villagers they shake their heads like normal (length of time, speed, and bow movement).

I also have this problem. I am on 1.14.3.  From what I have seen this problem seems to happen when the villager is not "assigned" its job site for whatever type of profession it has, such as a lectern for librarians.

I am able to get around this bug by crafting another job site matching the profession of the villager I am unable to trade with.  I place it down as close as possible to him and usually put him in a small room/cage.  The villager will then get reassigned his job site block and should then be able to resume trading as long as he remains assigned to a matching job site block. 

Due to villagers locking in their professions once you have traded with them once, they will not change appearance if their job site is removed and you will be unable to tell if they have a jobsite assigned to them unless you encounter this bug.

Duplicates MC-154201. This bug is fixed for 1.14.4.