Cue List sticks on the same cue each night.

Hi folks,

I'm running m429 on an old school Mac Pro with 10.6.8.

The show uses presets triggered by a Cue List, and consistently over the last four shows the cue list does not advance when the spacebar is pressed at one specific cue. A screenshot attached:

The cue runs two presets each of which fade up a layer - there's no media loading...
The third line triggers a custom serial command to un-shutter the projector - it's my prime suspect but other similar cues consistently run fine - this one consistently runs fine when testing but in show conditions consistently sticks - after a second or two another spacebar press runs it.

My only theory is that in show conditions it's been a while since a serial command has been run - can that interface be slow to "wake up" sometimes? (It's a command in the custom serial in the form of the url for the projector shutter off)

However the red dot does NOT move to that line in the cue list - it just sits on the first line as pictured - I added the 0.1 second wait time to see if that helped, but the problem persists.

It's as if it just ignores the space bar the first time. Last night - expecting it - we pressed again after maybe 1 second - that too didn't work. A couple of seconds later I pressed space again and it did work.

Any thoughts on the mystery welcome!

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