Ryobi 750 g - varnish tower

Could someone advise me and know why I get this error, and that's why I can't apply varnish.

 

What make of coater is on the press? Also, what was the year of manufacture? Is it that the pan is overfilling?

 

The coater tower has sensors that detect its position so the machine knows if it is down in printing position or up out of printing position.
One of the sensors is probably damaged or an adjustment needs to be made to its correct position.