Disturbance in drive of central mold height

I have a Nestal Evos 5500 injection molding machine, I got this alarm (Disturbance in drive of central mold height) I installed a new moog valve for the die height, still
have the same problem, checked the contactor and fuse, OK,

can any one help me with this problem, thank you for any and all information.

Is this a toggle clamp press? Maybe the drive can't rotate the nuts on the end of the tie bars? Have they been greased with the proper lubricant? All of this is relevant if this is a toggle press.
Rick