I had an unusual issue last night with Mach4.  After running 10 parts successfully, the lathe stopped working midway through the G-code file.  Apparently Mach4 dropped from enabled to disabled.  When I tried to re-enable, it took effect then after a few seconds shifted to disabled with no action on my part.

I restarted Mach4, Restarted and Shut down (then started) the computer.  No change -- the Mach4 software continues to "auto" shift from enabled to disabled.

Happened in the middle of a production run, so the CNC code is good, and no changes were made in the Mach4 configuration.

Should I re-install the most current version of Mach4? 

Hi,
That rather sounds like noise.

Its not impossible either that your motion control board is exhausting the motion buffer, and depending on the motion control that to will
cause an Estop, ie disable Mach.

Craig