Thanks Gill, that makes perfect sense.
As far as I am aware there is nothing running in the background, and I am certainly not attempting to run both Scheduler and Xlights at the same time, so there must be something "odd" with the old Quad-core Dell T610 server that I am using as a show machine, Win 7 and 10 Gig's of ram :-( Maybe a change of machine may help.
The lights are running perfectly as far as I am aware, using the scheduler and xLights it'self to test the setup sequence by sequence if necessary, as well as testing individual items. The only thing that isn't doing what it "should do" is the DMX feed which I can live without at this stage of the display season if necessary, hence my query in the other thread.
Something I did observe, which now adds up! On the first load-up of xLights to test the DMX, it produced the "error message" and the DMX was AWOL, if I closed xLights and the sequence, then re-loaded xLights with the same sequence, on most occasions the DMX operated as expected/programmed!! It must have cleared whatever flags were set on the second load, I will try that process with the scheduler and see if it has the same effect, although I have never seen that error message with the scheduler.
Thanks for your input, no sweat at all.
Terry