1) Flickering sun
Each time after I delete a world and create a new one, the sun is blinking, i.e. every second the time changes to night and then to day again. Every second or so. It fixes itself only after I quit the program and run it again. I've seen this problem reported by many users, but I found no solution.
2) Born dead?
Sometimes after I create a new world, the game will greet me by announcing that I'm dead, so I have to delete it and create another one. I guess this has something to do with the game copying elements from my last world; one time in a newly created world I found a cave lit up with torches - something I always do but can never be found naturally, right?
I believe errors 1 and 2 are connected with the program copying elements from the last game. It seems that the flickering is the game not being able to decide between the time from the previous game and the current one. Also, at times I would find elements in a current game that come definitely from a previous one, e.g. a house.
3) Chunk error
Sometimes a new world will look like it's been cut with a knife. It looks like this: https://bugs.mojang.com/browse/MC-2545 . It's not just a display error. The chunks are physically not there.
4) New recipes
Usually the game suggests new recipes correctly. Yet sometimes it will only add a recipe of an item only after I've crafted it.
5) Suicidal squids
I don't know if that's intentional but I believe not. Oftentimes a squid will swim against the bank and hurt itself until it's dead.
Comments 2
Please only report one issue per ticket, also use the search function before reporting an issue. See: Guide: Writing Helpful Bug Reports for Minecraft
I can confirm that I also had a couple of times that a new world had my inventory of a different worldsave showing for a very brief amount of time.
Havent recently focussed on that though, but if I happen to see it again, I'll comment again with the MC version number.