There was a previous post about this issue where you could hold Control + Drop (Q) and drag your mouse over items in your inventory, and they would all drop. This did not work in containers such as chests. The issue was stated as resolved, and in the latest version of minecraft, it is, but in 1.12.2 it is still broken. Is it possible to fix this?
THIS IS NOT AN ISSUE IN 1.21, it was the only label i could put.
MC-274650
Hold Drop and Drag Mouse in Containers
Resolved
Invalid
0
See my comment in MC-135973. You are playing an outdated version of the game. The newest version has all the previous fixes. You will need to update your game to fix this issue. Please don't report issues for older versions.