Game Crashed Whilst Ticking Block Entity

On a server I co-own, a redstone repeater clock, both set on second setting, connected to a sticky piston causes game to crash, with report of; "The game crashed whilst ticking block entity". Server still works completely fine.

Crash Report:

The game crashed whilst ticking block entity
The game crashed whilst ticking block entity
Error: java.lang.IllegalArgumentException: Cannot get property atw{name=facing, clazz=class cv, values=[down, up, north, south, west, east]} as it does not exist in atk{block=minecraft:air, properties=[]}