I have a SmoothStepper board and have SmoothStepper_Beta2_v015me.m3p installed with 3.042.014 and I get the follwong error when Mach3 loads:

Error Found Art Code 9991 Attempting Recovery
Error Triggered

When I click Yes I get this message again. When I click No I get the following message:

Mach4
Error Stopping Timer

The only choice is No and when I click that I get The above error message.

The only thing I can do is kill the application in Task Manager but it starts all over when I restart Mach3.

I updated to the latest development version of Mach3 and the latest beta driver for the Smoothstepper and the problem went away.