We just put a lathe into production and the operator tells me that it keeps shutting down Mach4 in random places while running a program.  It will run for a few hours just fine and then just close Mach4.
This is the first time I've had this issue using Mach4 on either mill or lathe profiles.
Using version 4300 HiCON Integra. 
Maybe something in the PLC script that is causing an error but usually a dialog box lets me know if something isn't correct; with this problem it just immediately closes Mach4 with no warning. 

What version are you on?

4300 Hobby
It's strange, I've got 4 or 5 machines running the same build on hobby with no issue.

We are getting version 4599 or maybe 4600 ready for release . My guess it will be 4600 ... But in 300 Versions we may have sorted that issue we are working all the time on the software to make it better for everyone!

Ok. I’ll give it a try. I do t use the lathe much; didn’t know if it was a lathe specific issue.

Don't matter to me if  you use it once a year it must be correct for you !

I put build 4599 on the lathe. Now when I go to do a canned cycle it goes to z0 and back to the initial point return. Side note: g98.1 and g99.1 aren’t working as expected. G98.1 adds whatever the r value is to the initial point and moves to that summed value. G99.1 returns to initia point. But that’s a different topic.
I’m getting this message.
@Capping a minimum to 0.0000 based on parameter 1801.
No idea what this is. Changing variable 1801 doesn’t change anything.

That is a Parameter in the parameter.ini file in the profile. I have someone looking to see if we can clean  up your profile. Looks like some of the settings are very old. Sorry but this will take a bit, and will only hurt a little

Further testing showed us that that setting is limiting our z travel. We can’t get z to move smaller than 0.00.

This is a Parameter that was in mill that we moved to lathe that didn't effect you before . You need to open the parameter.ini file in the profile. change the following to look like this with Mach4 OFF:

[1801]
Desc=OEM parameter 1801
Type=2
Value=NULL

The value is zero now... This is a place where you can change how Gcode is ran. Sort of cool you can limit the stroke of the Zaxis   . Please adjust that and tell me if your set.

Thanks and sorry for the troubles!
Brian