Lars

Deactivating the texture pack solves the problem. Is there something I need to change to the texture pack or will Mojang fix this?

Still in 1.15.2

In 20w06a however the fireball is only invisible for the first seconds and then works correctly

Workaround for 1.15.2

Summon fireball with initial "power" as mentioned earlier:

summon minecraft:fireball ~ ~ ~ {"direction":[0.0,0.0,0.0],"power":[0.0,-0.0002,0.0],"Tags":["wd_fireball0"]}

Setting the "power" back to 0 immediately:

execute as @e[type=minecraft:fireball,tag=wd_fireball0] run data merge entity @s {"power":[0.0,0.0,0.0],"Tags":[]}

The second command can be executed every tick.

This preserves the ability to interact with the fireball even so the power is 0 and the fireball is motionless.

It works on my iPad 2018 with iPadOS 13.2.2, is it only by me that it works or not?

Hitting fireballs with power greater than a certain amount seem to works.

/summon fireball ~ ~ ~ {direction:[0.0,0.0,0.0],power:[0.0,-0.0002,0.0]}

Tested on 1.14

I'm not an idiot. Like I said the farm works perfectly, but when I close the game and switch to version 1.10.1 or 1.10.2, the wheat farmer instantly stops farming. When I go back to 1.10 and put a new farmer there he immediately starts farming.

And it's not 'a while' I'm waiting, literally half of the wheat was already fully grown and the farmer did nothing.

You have to put all tags in quotes ("text":"hi")
For example:

/tellraw @a [{"text":"Lock has been ","color":"blue"},{"text":"Disabled!","color":"green","bold":"true"}]

The JSON format has changed.
Now you have to put all tags in quotes (its backward compatible so don't worry):

blockdata -3 38 1000 {
   Text1:"{\"text\":\"---------------\",\"color\":\"dark_green\"}",
   Text2:"{\"text\":\"[ START ]\",\"color\":\"dark_green\"}",
   Text3:"{\"text\":\"Click\",\"color\":\"green\",\"clickEvent\":{\"action\":\"run_command\",\"value\":\"/setblock 3 22 1000 minecraft:redstone_block\"}}",
   Text4:"{\"text\":\"----------------\",\"color\":\"dark_green\"}"}

Did you used the id numbers or the id names (like "minecraft:diamond_sword")? Please give us some examples.
It doesn't work with id numbers anymore, but it works fine with id names:

/give @p chest 1 0 {BlockEntityTag: {Items: [{id:"minecraft:diamond_sword", Slot: 13, Count: 42}]}, display: {Name: "hey"}}

There are two new tags:

/summon Skeleton ~ ~ ~ {ArmorItems:[{...},{...},{...},{...}],HandItems:[{...},{...}]}

(Order: "ArmorItems": feet, legs, chest, head | "HandItems": main hand, off hand)

They changed JSON-text.
This works anymore:

"[{text:\"Hi\"}]"

You have to put each argument ("text", "color"...) in quotes (backward compatible to 1.8):

/give @p written_book 1 0 {title:"A",author:Somebody,pages:["{\"text\":\"Hi\"}"]}

(And u have to define author and title too)

You can use JSON-Text to create colored text on signs:

blockdata ~ ~1 ~ {Text1:"{\"text\":\"Green\",\"color\":\"dark_green\"}",Text2:"{\"text\":\"Red\",\"color\":\"dark_red\"}",Text3:"{\"text\":\"Blue\",\"color\":\"blue\"}",Text4:"{\"text\":\"Yellow\",\"color\":\"yellow\"}"}

(Copy this in a command block and place a sign above it...)

This effects all Mobs that are spawned with spawn eggs!
Its impossible to select those mobs in commands with the target selection argument @e.
>>Error Massage: "That entity cannot be found".

SMP and SSP are pretty much the same, cause SSP is simply an local server + client. Maybe you have to update your sound engine jar. i heard from many people that they were having issues which are fixed after updating sound engine.

@Matthew whats your system specs ?? slow system ??

Maybe the server is running on a too slow machine or your ping is too high ...

I dont think its minecraft itself, cause nobody else has talked about such a bug. Maybe its a corrupt world file... Have you tried to create a new world ??