Chiron FZ 08 - Fixture not Clamped

[Etech17]

Am getting "A12.3" (Clamping Fixture Not Clamped) and "A14.3" (Protective Doors Not Open) error and on Chiron FZ 08 with GE Fanuc Series 21i-M controller. RESET clears the Doors error but not the Clamping error. The doors will still not open and the "Clamp/Unclamp" switch/lamp conitinually flashes.
The only way to get the doors open is to manually defeat the interlock swithches. Can someone suggest a remedy for this? Thought it might be air pressure but have adjusted that to no avail. Prior to this got doors to open once but cannot seem to repeat eventhough set conditions at control panel to exact conditions.

Thanks.