There is no error that is produced (i checked the console as well), the sprite priority no longer functions when having battlers overlap.
With the plugin i posted above, you can dictate the battlers sprite priority. It is functioning correctly in the left frame - battler on the left should have layer priority (JM_EarthboundBackgrounds disabled) and in the right frame ( with JM_EarthboundBackgrounds enabled), it no longer correctly takes sprite priority.
Where do you call
Spriteset_Battle.prototype.battleFieldDepthCompare
because it's not a default RMMV parameter, and that might be causing the error. My plugin overwrites
Spriteset_Battle.prototype.adjustSprite Spriteset_Battle.prototype.updateZCoordinates
Now that I think about it, if that plugin overwrites updateZCoordinates, it would be wiped clean by my plugin, so try including that plugin after EarthboundBackgrounds and see what happens.
Basically: Flip the order of the 2 plugins and see if that fixes things.
Sidenote: The reason the plugin overwrites
Spriteset_Battle.prototype.updateZCoordinates
is something about compatibility with Yanfly Battle Core. I might experiment later to see what exactly is going on, but it was replaced by a no-op...maybe it was messing with _back*Sprite which this plugin coerces.
