In a world without an icon every second this error appears in the game log:
[15:50:49] [Client thread/WARN]: Couldn't save auto screenshot
java.io.IOException: Could not write image to the PNG file "C:\Users\User\AppData\Roaming\minecraft\saves\Survival1_13\icon.png": Corrupt JPEG
at cgj.a(SourceFile:305) ~[17w45b.jar:?]
at bxm.n(SourceFile:1047) [17w45b.jar:?]
at bxm.a(SourceFile:957) [17w45b.jar:?]
at bko.b(SourceFile:811) [17w45b.jar:?]
at bko.a(SourceFile:370) [17w45b.jar:?]
at net.minecraft.client.main.Main.main(SourceFile:134) [17w45b.jar:?]Linked issues
duplicates 1
Comments 2
I have the same problem and I think this is not a duplicate of MC-121714, because I CAN take screenshots with F2 every time, but CANNOT create "succesfully" world icons in 1.12.2 and my world's path supposedly has only ASCII characters (only has a to z, A to Z, 0 to 9, the period of ".minecraft" and the colon of "C:"), but I can't/[don't know how to] confirm the encoding of that characters.
On some worlds worked, but in other it is never created, at world creation, or (in other worlds) can't be re-taked.
I have made an experiment creating an icon.png file of 64x64 pixels with an image editor, then I inserted it in the world folder, started MC and it appeared as expected in the world selection menu. Then I clicked Reset Icon and the only thing that hapen is that the file gets removed and the world icon is never created when entering the world and wait more than "no matter the number of" hours, even repeating multiple times the said process, with another copies of the icon, in the same world.
In some ocasions (maybe with worlds created some versions before) it might work after ~10 min, but that is very rare.
Can't you save screenshot either? And each world in your version either?