Green0 Sorry to hear about your problems.
Clamping issue with the C axis during light cuts or both A and C. Is the error a clamp error or out of position error? We had one that did it with the C axis The tech found that the bad brake seals allowed air to pressurize the cavity of the rotary keeping the brake from working..
there is no physical brake confirmation is is just a pressure switch. if the cavity is pressurized you can check by pulling out the oil fill plug on the a axis or turning the C up and pulling out the oil inspection/fill plug on the side. be careful it that is the issue it may blow the cap off when you are pulling it out.
best way to contact Hurco service is email [email protected] with machine serial number. description of the problem and a naverror file If you can get it.