While preprocessing a file, the computer freezes every time (the issue is not solved by a reboot and another attempt at preprocessing)
Frequently, the system freezes at or around 50% preprocess. If left for a very long time, it might increase a few percentage points.
The system is preprocessing the files at a very low cut speed. The amount of time a file takes to preprocess is proportional to the amount of time the file will take to run. Feed speeds less than 1 unit per minute typically result in this behavior.
Check to see if the feeds and speeds are set to override. This is in the first menu of setup, under preprogrammed or override speeds. If the speeds are set to override, the values for the overridden speeds are likely too low.
If the system is set to programmed speeds, it is likely that the speeds set in the file by your CAM software are too low. Edit the file and look for F commands followed by a number - this is the speed. It is common for CAM software that has not been set up properly to output a speed of F0.1 . Either override the speeds or re-post the file with a reasonable speed.