Occasionally I get this obscure bug. It plainly is a bug, although reproducing it is another matter!

I think this time it occurred when I hit the Space key while playing an object. Track 1 then went black and dragging the orange time marker created multiple vertical lines in track 1. If I play from any point, then they form a solid 'bar' as shown. I can only save and restart.

Ring any bells?

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Terry, East Grinstead, UK