I have farms that the villagers are set up in to work in and the farming one always disappears after a while of the chunks being unloaded. I'm always having to replace the brown coat and it's getting very frustrating.
Related issues
Comments
this is still happening for me as well. today the 1.2.11 update dropped and i see nothing in the bug fix description mentioning a fix.
the villagers seem to disappear most after i have shut down the world and come back to play the next day. the hopper minecart under the farm is gone at the same time too. i'm not sure loading and unloading chunks affects it while i am playing as i have not noticed losing a farmer during play. i have come to be in the habit of checking on my farmers as they are disappearing so much and these are the timelines i have noticed.
Is it possible that the villagers are standing on the boundary of two chunks? If so, there is a chance that they are despawning if the game crashes, as they are not fully in a particular chunk.
You can use a simple calculation to figure out where the chunk boundaries are (each chunk is 16x16 blocks), these links might help you: http://chunkbase.com/apps/slime-finder and https://dinnerbone.com/minecraft/tools/coordinates/.
i do not think this is our issue. we are playing on realms (or bedrock i believe) on the xbox. there are two of us playing on this world both having the same problem. there are no crashes that we know of at the times we lose villagers. we are losing automatic farming villagers after we log out. they are just gone (like a fart in the wind) after we log back in. i have lost 3 villagers in the last 2 logouts. i have 3 farms, wheat, carrots, potatoes, and a limited space where farming even works. if you are saying we can't build a farm on a chunk border this would severely limit the space available to build an automatic farm, not to mention i have never heard of this possibility and i have watched a lot of you-tube videos and never heard of this issue with borders.
we both lose our farming villagers when we log out. not every time but enough to be very annoying. my losing 3 farmers in two logouts is an extreme. most farmers usually last 3 or 4 days. if i get a week out a farmer i am happy these days and that is an unfortunate situation.
we have tried naming our villagers, no joy. we have tried quitting minecraft from the home screen after we log out thinking something may still be running, no joy. we know it is not loss due to lightning hitting villagers underground and turning them into witches - a whole other issue that is making us mad.
i have noticed that i never lose a villager inside a 1 by 1 cell and i have a lot of trading villagers penned up. so, our next idea for a fix is to lure our farmers into a 1 by 1 cell before every logout. we would lure the farmer with a ripe crop and lock him in quickly when he went for it. not an ideal solution, and hopefully not a long term one either...hint, hint, hint.
so more description. if you want logs or pics i'll have to figure out how to get them on here from an xbox. i'm doing this from my PC.
two players on the world each having their own complexes - village, farms, house blah blah blah. each having same problem.
the village model we both use is similar. we each have an iron golem farm with a 18x18 pad of flowing water pushing golems to the center built at/ near ground level. under that we keep all the villagers - so all underground housing but as close as possible to the surface. here we each keep many jailed up villagers for trading in 1x1 cells, i probably have around 20 of these myself. then we have our farms/farming villagers and our hungry villagers that get food thrown at them. lots of villagers, yes, but as of yesterday the breeding villagers can still have babies when i give them food so i am not over the population breeding limit by importing villagers from elsewhere. losing the jailed up villagers to lightning is still a problem even though they are all underground, the witches we have found in the jail cells, this is not the issue we are trying to get fixed. we are losing loose roaming farmers locked in 9x9 or 9x18 auto-farms and it happens when we logout - 99% sure.
the hopper mine cart under the wheat farm disappears in the same fashion on logouts. its like a villager, it could last a day or 7 days. the circumstances are similar making me think they are related - which is why I mentioned it now and above
so the 1x1 cell idea above seems to be working. i describe what i did here, https://bugs.mojang.com/browse/MCPE-26338
MCPE-26338

I can confirm this, although not for farms. In a villager breeder in survival Realms, many of our villagers frequently despawn. So far, we've unfortunately lost a mending librarian, respiration librarian, 2 clerics, and a weapon smith.
lock them in 1x1 cells. i have not lost a single locked up villager since i started on this realms server several months ago. i guessed 20 above but then i counted 32 locked up of every denomination (mostly librarians).
if you already have them locked up and you are still losing them then i don't know what to tell you. move the cells a few blocks over if possible - is there a pattern which jail cells you are losing them out of, don't use those, sorry not sure.
and check them after a lightning storm. lightning turns villagers into witches and witches despawn. this has been happening to us even with underground villagers - another bug for another day.
Thank you for your report!
However, this issue has been closed as a Duplicate of MCPE-21416.
Please add a vote and any new information to the main ticket, which will be updated accordingly.
If you have not, you might like to make use of the search feature before making a new ticket, as it's likely that the issue has been reported already.
Quick Links:
📓 Issue Guidelines – 💬 Community Support – 📧 Feedback – 📖 Game Wiki
I can confirm this. However, I do not think it is due to chunk loading/unloading. I have a villager (for a wheat farm) set in a ticking area (so it is not unloaded). Both the villager and the hopper minecarts I have underneath the farm disappear randomly. It is not affected by going to the nether because I often do that and the villager is fine. I have done the troubleshooting of interacting with the villager and the hopper minecarts (which in an eariler version fixed this issue), but it does not seem to have an effect.