It is working fine for me, it might be with the missing .keyframe file
Restart Mine-imator, and if it still doesnt work. Try reinstalling or downloading Mine-imator again
And if it still doesnt work, you gotta go report the bug.
as hard as it is to make a walk cycle, you gotta animate it manually like Pigeon said. That's the only way to make a good walk cycle
Hope it helps