Additional Information
Turned on logging  (log file data attached)  
found that when using GoToWorkZero Screen Button, the following command is issued
API: mcCntlMdiExecute(inst = 0, commands = 'G00 G53 Z0G00 X0 YO G00 Z0') (unknown caller)
When using the VistaCNC P2-S4 Pendant, this command is issued
API: mcCntlGotoZero(inst = 0) (unknown caller)
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From the API reference document, 
rc = mc.mcCntlGotoZero(number mInst)
Description:
Move the X,Y,A,B,C and then the Z axis to zero of the current fixture offset. 
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I have A,B,C all disabled, only using X,Y,Z and getting the error message "Axis 3 commanded while disabled"
If I enable Axis A , then I get and error "Axis 4 commanded while disabled"  which makes no sense to me. 
it appears that possible something is not quite right in the API, enabling an Axis, causing the "Axis x commanded while disabled" error to occur. 
anyone have any thoughts?