/setblock ~1 ~ ~ chest 0 replace {Items:[{id:256,Slot:0,Count:1},{id:257,Slot:1,Count:1}]}
1.8.9 (Working)
https://youtu.be/7wGOyKHPovg
1.9 (Not Working)
https://youtu.be/EShuDV4xcsE
MC-99620
Chest filling with commandblock, dataTag doesn't work in 1.9 or newer version
Resolved
Invalid
0
In 1.9 id must be a string, not a number (F3+H to see id of the item)