Ryobi 756 6 col press, error code E-P-308

Hello everyone.
Just wondering if anyone had any idea what E-P-308 error code signifies?
The issue is ,when pressing remove plate button ,the cylinder reverses into position, then just cuts out ,therefore displaying the error code.this issue is repeated on all 6 units.
Any help on this matter would be greatly appreciated.
Kind regards
Jason

 

Could it be low airpressur turn it a bit up and try again

 

We ran into a compressed air problem on the 524GX.
The main problem is the anti-staining powder.
We have a standard Rietschle oil-free piston compressor installed on the drive side behind the feeder. Printing with powder 4+4.
As a result, the pneumatic system is clogged with powder. Throttle regulators for removing and installing plates, pneumatic mufflers, inlet pressure regulator - steam trap. Requires periodic cleaning and purging, exhaust mufflers are a consumable spare part.
The muffler that is in the screen photograph is replaced 4 times a year, 4 pieces each.
Throttles of plate cylinder locks are blown 4 times a year. In our machine, they are located on the control side behind the high section covers.
Larger mufflers are also damaged by the powder. It is useless to rinse and blow, they did not try with ultrasound.
Official website of the CKD manufacturer, catalog page:
https://www.ckd.co.jp/kiki/en/general_catalog/