Farmer has everything but Hat, has leaf headband and cannot open

This is an "unemployed" villager in a Savanna biome. The green particles are probably due to linking to a bed. Place a composter and one of them will probably become a farmer. See https://minecraft.gamepedia.com/Villager#Professions for images of all of the villager types.

Thank you for that. I looked for the same in the villager description, but I guess not hard enough. They don't take a job though. They took a bed and a composter but don't change to a farmer, they just stay unemployed.

I could be wrong (it might just be the FoV - or I could be spacing out, I'm less confident the more I look at it) but those appear to be baby villagers, not grown, so would be unable to trade with until they grow up.

I'm going to close this off as Incomplete though, based purely off the description its not possible for someone to reproduce this reliably. If you have steps on how to reproduce the issue please feel free to log a new report.

For more information on the information we need in a bug report please head over to http://help.mojang.com/customer/portal/articles/801354-writing-helpful-bug-reports-for-minecraft

Quick Links:
📓 Issue Guidelines – 💬 Community Support – 📧 Customer Support – ✍️ Feedback and Suggestions – 📖 Game Wiki