: If your physical dongle is confirmed defective (light is off even in multiple ports), you should contact DRAWings Support to discuss a replacement or digital migration.
This error message typically appears during the launch of the DRAWings software. "CBU" stands for the specialized drivers (Marx CBUSetup) that manage the hardware dongle. When this failure occurs, it means the communication link between the software and the physical USB key is broken.
The X3 temporal drawing shows the spool position drifting by 0.002mm every 10,000 cycles.