@Wolfgang I have a reproducible error so I will submit a support request, because I don’t have a premium subscription it will be interesting to see how long it takes to get a response! If they then suggest I reproduce the problem with a logging option set then I can do that and hopefully it will point to what is going wrong.
At a guess it is caused by the number of images in the batch which are then causing the software to trip itself up, e.g. using resources, adding to arrays etc. etc. .
So when I remove images from one point in the selection the problem moves down the selection and that repeats itself every time I leave “problem” images out of the selection. It would have vanished completely if I de-selected sufficient images that the “error(s)” were not then encountered.
Whether another export would have cleared the problem or simply encountered the problem even sooner. Terminating the export worker should prevent that kind on knock on effect (if it exists).
A bit like this
Two runs of the same export selection that stopped at the point where the earlier test first failed with the second run scheduled before the first had finished.
The first export run was fine and the next failed on the first image, exactly the same point it would have failed with the original test selection.
Between the two pairs of runs there was a gap while I wrote part of this and it seems that the breathing space was sufficient for the software not to fail again during run 3 .