The "Done" button does not become clickable/unclickable at the right times.
How to reproduce:
Place a new commandblock
See how the "Done" button is available to click
Press on a key while in the interface, this makes the "Done" button unclickable (except for F2, because this button has a functionality when in the interface). This even happens if you click outside of the command box and click on a key
The "Done" button will only appear again if you press a key again AND there are at least 2 characters in the command input box.
Linked issues
Comments 2
Duplicates MC-121377
Just nitpicking - one character in the input box is enough if you then press a button while the text box is not focused 😉