The crosshair Attack Indicator is not displaying in the Debug Mode.
(I tested it in all called Versions, I only made the picture in 1.9.2)
MC-101421
Crosshair Attack Indicator displaying Bug
Resolved
Duplicate
0
(Unassigned)
Unconfirmed
Minecraft 1.9.2, Minecraft 16w14a, Minecraft 16w15a, Minecraft 16w15b, Minecraft 1.9.3 Pre-Release 1, Minecraft 1.9.3 Pre-Release 2
Retrieved
Anything that works fine outside of the debug menu and not within it is a won't fix, see MC-86657.