Can anyone give me some input on ADB for mac...trying to sideload

It is showing the following when trying to move a ROM over via ADB on my mac

Last login: Sun Nov 23 23:12:08 on ttys000
FurnsMBP2:~ j311slx1986$ cd downloads
FurnsMBP2:downloads j311slx1986$ cd fastboot
FurnsMBP2:fastboot j311slx1986$ chmod 755 *
FurnsMBP2:fastboot j311slx1986$ ./adb-mac devices
List of devices attached
LGD8508fef8db6 sideload

FurnsMBP2:fastboot j311slx1986$ ./adb-mac push BIN_LGD850AT-01-V10d-310-410-JUN-19-2014-0.zip /sdcard/.
error: closed
FurnsMBP2:fastboot j311slx1986$


Using the ADB sideload feature in TWRP recovery, it stays on the screen that says "Starting ADB sideload feature", but obviously is connected as it is showing the device


Thanks for any input